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LABORATORY LESSONS IN GENERAL 
SCIENCE 



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THE MACMILLAN COMPANY 

NEW YORK • BOSTON • CHICAGO • DALLAS 
ATLANTA • SAN FRANCISCO 

MACMILLAN & CO., Limited 

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THE MACMILLAN CO. OF CANADA, Ltd. 

TORONTO 



LABORATORY LESSONS 

IN 

GENERAL SCIENCE 



BY 



HERBERT BROWNELL, B.Sc. 

PROFESSOR OF SCIENCES IN SECONDARY EDUCATION ; AUTHOR OF 

"LESSONS IN PHYSICS," AND "LESSONS IN CHEMISTRY" 

TEACHERS COLLEGE, UNIVERSITY OF NEBRASKA 

LINCOLN, NEBRASKA 



THE MACMILLAN COMPANY 

1916 

All rights reserved 






COPYBIGHT, 1916, 

By THE MACMILLAN COMPANY. 



Set up and electrotyped. Published June, 1916. 




Norbjootj $ress 

J. S. Cushing Co. — Berwick & Smith Co. 

Norwood, Mass., U.S.A. 

JUN 16 1916 
©CI.A433388 



*Wo 



PREFACE 

This set of laboratory exercises in general science is an 
outgrowth of courses given by the author in methods of 
teaching secondary school sciences. Some of the lessons 
represent the combined efforts of a class upon an assigned 
topic, but so reshaped that credit to any individual is out 
of question. Free use has been made of material from 
the author's Lessons in Astronomy, Chemistry, Nature 
Study, and Physics — manuals prepared for his own class 
work. Many of the exercises have enough material for 
more than one lesson, and should be subdivided to suit 
teaching conditions. 

The preparation of these lessons was stimulated by the 
belief that one chief cause of failure to get desired results 
with beginning classes in the high school sciences lay in 
the character of the material chosen. It was believed 
possible to bring together from scattered sources that 
which would appeal to beginners and which would find 
its unity in their life experiences and interests. This 
involved the rejection of much material of great worth 
from the differentiated high school sciences that is un- 
suited for an elementary course. Teachers subject to the 
exactions of schoolroom service do not have the time to 
make selections of material and properly to relate and 
adapt them for use. 

The fund of life experiences available for a laboratory 
course about which science instruction of a general and 



vi PREFACE 

elementary nature may center is large and should be more 
freely used by science teachers in secondary schools. 
These life experiences, supplemented by the experimental 
knowledge gained under direction in school, makes possible 
a fuller understanding of the teachings of books and a 
ready acquisition and grouping of a wide range of facts. 

The emphasis placed in these lessons upon the interests 
of the individual, in both their personal and their com- 
munity aspects, is expression of a conviction on the part 
of the author that topics of social science should not only 
be included in a general science course but should be 
treated in much the same w^ay as are topics from the 
various fields of the natural sciences. Any unification of 
life interests and life problems with the spirit and pro- 
cedure in science studies not only enriches the science 
teaching but reacts upon the daily living to make it more 
sane and more wisely ordered. 

School work that requires discrimination in the impor- 
tance of the facts involved in the affairs of life, that notes 
the bearing of these facts upon the well-being of the indi- 
vidual, and that formulates a rational course of action, 
not only develops a scientific attitude but it constitutes a 
training of inestimable worth in the education of youth. 
The varied interests of pupils are thus made centers about 
which to group newly acquired knowledge. 

It is the author's belief that differentiation between the 
various sciences may be disregarded during the first year 
in high school. Emphasis is placed instead upon an inter- 
pretation of related scientific phenomena regardless of the 
fields into which any inquiry may lead. The relationship 
and unity indispensable in science studies is secured 
through a grouping of the interests and experiences of the 



PREFACE Vll 

pupils rather than in the principles and laws of any branch 
of science. And it has been the aim to select as material 
for study not only that which is valuable in itself but that 
which at the same time is likely to be a stimulus in a truly 
educative process. 

The author wishes to express his appreciation of the 
helpful suggestions and criticisms coming from those who 
have read the manuscript of these lessons. He desires 
especially to thank Professor George E. Martin, Head of 
the Department of English in the State Normal School at 
Kearney ; and Dr. R. J. Pool, Professor of Botany in the 
State University at Lincoln. He is greatly indebted, too, 
for helpful suggestions from the following who have read 
portions of the manuscript : Miss Alice Loomis, Head of 
the Department of Home Economics at the State Univer- 
sity of Nebraska; George E. Loveland, Professor of 
Meteorology in the State University and Director of the 
U. S. Weather Bureau; Dean E. L. Rouse, Superintend- 
ent of Practice in the State Normal School at Peru; 
Professor H. C. Filley, Head of the Department of Farm 
Management in the College of Agriculture ; and Professor 
B. C. Hendricks of the Department of Physics in the 
State Normal School at Peru. 

HERBERT BROWNELL. 

Lincoln, Nebraska. 
1916. 



CONTENTS 

Lessons marked with an asterisk [*] are somewhat more difficult than the others, and 
may when desired be deferred or omitted. Usually this will be unnecessary. 

PAGE 

I. The Human Body .... 1 

The hand. — The mouth. — The eye. 

II. Heat in Relation to the Human Body . 9 

Combustion. — Ventilation. — Respiration. — The human 
body as an engine. — Regulation of the body temperature. 

III. Health and Well-Being ... 19 

Keeping well. — Infection. — Sanitation. — The water supply 
and health. — General health problems. — Life, growth, rest, 
and recreation. — Stimulants and narcotics. — General science 
and right living. 

IV. Matter and Force ... 38 

Some properties of matter, and changes in matter due to force. 

V. Water and Its Uses ... 41 

Some properties of water. — Vaporization and condensation. 
— Heat of vaporization and of fusion. — Solution, absorption, 
and diffusion. — Osmosis in the body and in plants. — Study of 
a stream. — Valley formation and surface erosion. 

VI. The Atmosphere .... 53 

Some properties and uses of air. — Pressure exerted by the 
atmosphere. — Applications of atmospheric pressure. — Causes 
of change in atmospheric pressure. — Currents in the atmos- 
phere. — Areas of high and low pressure.* 



X CONTENTS 

PAGE 

VII. Weather and Climate ... 63 

Weather in the affairs of men. — Weather as affected by highs 
and lows.* — The thermometer. — Temperature records. — Solar 
heating.* General weather records.* 

VIII. At Our Homes .... 77 

Rooms of the house and their furnishings. — The cost of liv- 
ing. — Fires and burns. — Accidents other than burns. 

IX. Household Chemistry ... 94 

A review of some chemical changes. — The chemistry of clean- 
ing. — Acids, bases, and salts. — Some carbonates.* 

X. The Home Surroundings . . . 101 

A garden in the life of a family. — The care of a garden. — 
Tree planting. — Trees of the neighborhood. — Some plant 
studies. — Birds about our homes. 



XL Local Industries .... 117 

Some occupations of the community. — Modern industrial 
life. — Sanitary conditions for the wage earner. 



XII. The Farm, and Our Food Supplies . 124 

The hen. — Eggs. — Poultry keeping. — The horse. — Cows 
and the dairy industry. — Some foodstuffs. — Lessons on corn. — 
Fruits, and apple raising as an industry. — Wheat and wheat 
growing. — Other foodstuffs. — Origin and nature of soils. — 
Soil conditions in plant growth. — Usefulness of plants to man. 



XIII. Work and Machines . . . 160 

Meaning of the terms work and energy. — Measurement of 
work and energy. — Classes of levers. — Pulleys.* 



CONTENTS XI 

PAGE 

XIV. Magnetism and Electricity . . 167 

Electromagnets. — Electricity and chemical changes. 



XV. Phenomena of Light . . . 172 

Shadows and eclipses.* — Images by reflection. — Color phe- 
nomena.* 

XVI. The Earth as a Planet . . .180 

Day and night and the earth's rotation. — Rotation combined 
with revolution and changes in seasons.* — The moon and its 
phenomena. — Time and time-keeping, and standard time.* 



XVII. The Heavens* .... 193 



SUGGESTIONS TO TEACHERS 

From his own observations and experiences the author 
ventures the following suggestions with the hope that they 
may be of assistance to teachers generally. 

I. Laboratory Exercises 

1. The laboratory requirements should demand no large 
degree of skill in manipulation of apparatus. In some of 
the lessons, better results will be attained if the teacher 
performs part or all of the experiments. Every exercise 
should be so shaped that it not only challenges attention 
to its results, but provokes inquiry concerning the mean- 
ing of what is noted. At all times large use should be 
made of the experiences of the pupils in order to secure a 
comprehension of experimental phenomena and an under- 
standing of every new requirement of the lessons. 

2. Very satisfactory results are attained where one 
period is given over to a discussion of the requirements 
of a laboratory exercise item by item without previous study 
having been required of the pupils. In this way there is in 
the class discussions a zest that comes from having some- 
thing new, something that has not before been "studied." 
The common experiences of pupils and what has been 
learned in previous lessons afford ample preparation for 
such discussions. In this way it becomes possible not 
only to assemble and organize the knowledge possessed by 



xiv SUGGESTIONS TO TEACHERS 

all the pupils, but to get before the individual pupils the 
results of the class thought as corrected and related under 
guidance of the teacher. A second period spent in the 
laboratory or elsewhere can then be given over to writing 
the results of these requirements, with such use of refer- 
ence books as shall make this second period a study period 
even as was the first. These " laboratory papers," when 
returned to the pupils, should be preserved by them as 
their notebooks. 

3. Assistance given pupils during these preparation 
(laboratory) hours may be of such nature that a consistent 
training in the neglected art of study is secured. To 
learn whence to get desired information, whether from 
books or from experimental data, and how best to proceed 
in acquiring it, ought to be one of the large factors in an 
education. 

4. Some of the papers handed in at the close of every 
laboratory period must be carefully reviewed and cor- 
rected. All should be returned to the pupils before the 
next class period, some of them being marked " Not re- 
viewed " when necessary. There is no more important 
means of securing information concerning the ability of 
individual pupils, and no better guide to teaching pro- 
cedure, than is found in the review of some laboratory 
papers out of every set handed in. Often it is well to 
look over the papers of the same pupil every time for a 
while. 

II. Class Work 

All corrections and explanations of a general nature 
found necessary in a review of the laboratory papers 
should be made by the teacher during the class period. 



SUGGESTIONS TO TEACHERS XV 

Here is an unexcelled opportunity to impart much infor- 
mation that is closely related to what has been learned. 
Additional simple but instructive experiments by the 
teacher may be introduced here. The class-knowledge 
of each topic, whether gained from experience, learned in 
the laboratory, or gathered from books, is to be associated 
and unified by the teacher. If the laboratory hour be 
regarded as a time of preparation for instruction, the 
succeeding class period is a time for teaching. 

When a textbook is used, or any large amount of refer- 
ence reading is assigned, the teaching plan must provide 
for class periods given over more or less to quizzes upon 
the assignment, and to discussions and explanations to 
make sure that the readings are understood. 



LABORATORY LESSONS IN GENERAL 

SCIENCE 

I. LESSONS ON THE HUMAN BODY 

To the Pupil. — In the lessons that follow much useful information 
may be learned about many things with which we are already more or 
less acquainted. Wherever it is possible we shall study these things 
directly, and try to answer important questions about them. To the 
information gained in this way we shall in many cases add the knowl- 
edge gained from books. From these observations, from experiments, 
and from books, we are to get all the information we can. Every ques- 
tion asked and every requirement made is of the nature of a problem 
for us to solve. We are expected to find a reasonable answer for it. 
Sometimes we shall want to know not only that a certain thing is true, 
but why it is true, and what difference it would make to us if it were 
not true. That means that we must not only learn the facts, but we 
must consider what they mean. The questions asked will guide us in 
doing this. Doubtless many other questions will occur to you whose 
answers you will want to know. Consult freely all books at hand 
likely to give the information you want. 

THE HAND 

l. 1 Which part of the arm as a whole is the hand ? What 
name is given the part where the hand joins the forearm ? 

2. After moving the fingers in all possible directions, state 
what is true (a) of the freedom and variety in their move- 
ments ; (6) of the number of muscles required for these 
movements. 

1 In these laboratory exercises the paragraph numbering is to be observed 
in the written work handed in. This will aid in the correction of the papers. 
B 1 



LABORATORY LESSONS IN GENERAL SCIENCE 



3. While the left wrist is held in a close grasp by the right 
hand, observe any movements through the wrist as the 
fingers of the left hand are moved 
about. Explain what is seen and felt. 
Take firm hold of the forearm just 
below the elbow; move the fingers 
freely, and explain any movements 
noted in the arm. What purposes are 
served by having these muscles so far 
away from the parts moved by them ? 




Tendon, 



Muscle. 



Fig. 1. — Muscles and ten- 
dons of the hand and 
forearm. 



4. By what other means than the 
use of many muscles is variety in 
movements of the hand secured? 
Count the bones (a) in each finger, 
and in the thumb; (6) across the 
thick part of the hand. What pur- 
poses are served* (a) by binding to- 
gether the bones forming the palm 
of the hand ; (b) by having the thumb 
so loosely connected? What advan- 
tage results from having one less 
bone in the thumb than in a finger? 



5. What name is given to the inner 
side of the thick part of the hand? 
What is the name given to the union of any two 
bones? What special name is given the places where 
the fingers are joined to the hand ? What kind of motion 
only is possible in the joints of a finger? What purpose 
is served by these limitations in the freedom of finger 
movements ? 



LESSONS ON THE HUMAN BODY 3 

6. State very definitely the location of the nail on a finger. 
Describe the general shape of the finger nails, and any mark- 
ings on them. What is peculiar in the growth of the nails? 
What are their uses ? What care should be given them ? 

7. Describe the appearance of the skin in the palm of the 
hand. What variations are noted in its thickness? Ac- 
count for the deep 
markings in the palm 
of the hand. 



Hair 



fpiofermis 



Touch 
body 

fat- 
Sweat 
gJand 



Fig. 2. - 




8. Name several 
important uses of the 
hand. State what 
difficulties would be 
experienced by a per- 
son who had lost both 
hands. Because of 
lack of hands how 
must animals feed themselves ? What is true in a general 
way of the adaptation of the hand for ministering to the 
needs of man? Name several uses of the hand that il- 
lustrate the skill to which it may attain. By what means 
are hands and fingers made to act in obedience to the 
mind? 



• Cross section of the skin greatly 
magnified. 



THE MOUTH 

1. In what part of the head is the mouth cavity? Name 
the walls by which it is surrounded. To what else besides 
the cavity is the term mouth applied ? 

2. Describe the structure of the lips. What is the form 
and size of opening between the lips when wide apart ? How 



LABORATORY LESSONS IN GENERAL SCIENCE 



much freedom of motion have the lips, and how is this se- 
cured ? Name the several uses of the lips. 

What can be told of a person's feelings by noting the lips ? 
How may lip expression be affected by an oft-repeated 
emotion? Explain the redness of the inner surfaces of the 
lips and of their edges. 

3. Of what use are the cheeks? What is their structure? 

4. Observe the rear wall of your mouth as seen in a small 
mirror, and describe what you se$. Name its various parts. 

What is the name 
of the cavity farther 
back? 

5. What is the 
character of the roof 
of the mouth ? 
Which wall of the 
nasal cavity is it? 
If all the walls of 
the mouth were of 
bone, in what re- 
spects would its use- 
fulness be affected? 

6. Describe the 
structure, lining, 
and general appear- 
ance of the floor 
of the mouth after 

studying it closely with the aid of a mirror. Note the 
movements and the structure of the tongue, and explain its 
mobility. With the finger-tips pressed against the outside 




Tongue 



Fig. 3. — The mouth cavity. 



LESSONS ON THE HUMAN BODY 



of the throat about where the tongue seems to be rooted, 
ascertain if possible to what it is attached. Of what ad- 
vantage is an attachment of this kind ? 

7. Describe the form, size, color, and coverings of 
the tongue. Note how it may be rubbed against the 
roof of the mouth, and state what is accomplished by 
this action in eating. Mention other uses of the tongue 
in eating. 

8. For a person who is in good health what is the ap- 
pearance of the tongue as to (a) moist look; (h) coatings? 
What information is really sought by the physician when he 
" looks at the tongue"? What is tonsillitis (ton-si-ll'tis) ? 

9. State the location of the 
teeth in the mouth cavity, and 
their general arrangement. Why 
would it not be as well to have 
muscle in place of bone for the 
jaws? 

10. State the number, general 
characteristics, and duration (a) of 
the first set of teeth; (b) of the 
permanent set. Classify the per- 
manent teeth according to form. 
State the number, form and special 
use of each of these groups. 

11. Name the parts of a tooth. 
W 7 hich part is exposed in the 
mouth? What are the gums? 
W T hy should we take good care of 
the teeth ? How often should at- 




Bone | 

Cement or crusta petrosa 
Alveolar periosteum or root-membrane 



Fig. 4. — Cross- section of a 
tooth. 



6 LABORATORY LESSONS IN GENERAL SCIENCE 

tention be given them? What should be done, and what 
avoided, in order to preserve the teeth? 

Make a study of a tooth obtained from a dentist, or else- 
where, and tell the place and nature of (a) dentine; (b) 
enamel; (c) pulp. 

12. Where are the voice sounds produced? What is 
the function of the mouth in speech? What are the bad 
results of breathing through the mouth? What are ade- 
noids, and when may their removal become necessary? 

13. Aside from its use in speech, what is the chief use of 
the mouth ? What uses has the saliva ? By what is its flow 
affected? Where is it secreted? 

THE EYE 1 

1. Describe the location of your eyes with regard (a) to 
the body as a whole ; (6) to the face as a whole ; (c) to the 
nose. 

2. Of the eyeball tell (a) its estimated diameter; (6) 
the general form of it as seen with the eyes widely opened ; 
(c) the names of the several visible parts ; (d) the form, color 
and relative position of each part. In which part of the 
eyeball can changes in size be noted ? 

3. Watch closely the movements of the eyeball, and tell 
in what directions it can be made to move. 

4. Make observations of the eyes of several people and 
state what differences you observe (a) in the depth to which 
the eyes are set in the head ; (b) in the amount of ball exposed ; 

1 Use a small mirror for the study of your own eye. 



LESSONS ON THE HUMAN BODY 



(c) in the general appearance, luster, expression, movement 
and other characteristics. 

5. Mention any important purpose apparently served 
by having the eyes placed (a) so high up in the body; (b) 
at the surface rather than deeply set. 

6. What protection has the eyeball (a) at the sides; 
(b) in front? 

7. Of the eyelids state (a) the significance of the name ; 
(6) their structure; (c) the form of each when the eye is 
closed and when open ; (d) their relative size ; (e) the amount 
of motion for each ; (/) the place of the eyelashes. 

8. Describe the nature, form and length of the eye- 
lashes. What is their apparent purpose? 

9. State (a) what would result if the secretion of the 
tears were to cease; (b) how the tear-water is spread over 
the eyeball ; (c) how much 
of the time the eyeball is 
kept moist ; (d) from what 
point under the lids the 
tears flow; (e) the signifi- 
cance of water running from 
the nose when one cries; 
(/) why the tears do not 
overflow the cheeks all the 
time; (g) the course of the tears across the ball. 

10. When a bit of dirt or any solid particle gets under the 
eyelid, what may be done to remove it ? 

11. What uses have the eyebrows? In what respects 
are they unlike in different people ? 




Fig. 5. — The tears. 



8 LABORATORY LESSONS IN GENERAL SCIENCE 

12. What defects of the eye are common? 

13. What care should be taken of the eyes as to (a) di- 
rection whence light comes; (b) amount of light; (c) con- 
tinuous use of the eyes ; (d) general health ? 

14. Discuss briefly the importance of sight. 



II. HEAT IN RELATION TO THE HUMAN BODY 

COMBUSTION 

1. Put a long, narrow lamp chimney down over a short 
lighted candle set in a dish containing a little water. Re- 
peat several times, and state what occurs. Account for 
the result. 

Repeat these tests, having a partition of tin reaching 
down through the chimney at one side of the burning candle. 
Hold an extinguished match that is still smoking at the top 
of the chimney, first on one side of the tin and then on the 
other, and observe the smoke. What is the significance of 
the behavior of the smoke ? 

2. Let the teacher carefully melt a little potassium chlo- 
rate in a test tube, and then heat it to boiling. Observe the 
results as bits of match sticks are dropped into the hot 
liquid. 1 

The gas, oxygen, is set free from the chlorate as result of 
a chemical change, and the union of the oxygen with the 
wood is another chemical change. 

What is true (a) of the nature of combustion; (b) of the 
composition of air in order that it may support combustion 
of the candle ? 

1 It will be a wise precaution to fold a strip of paper into several thick- 
nesses, and wrap it about the upper end of the test tube as a holder. If the 
tube be heated nearly its full length at first, there will be less likelihood of 
breaking it when water from the crystals of the chlorate is driven off. 

9 



10 LABORATORY LESSONS IN GENERAL SCIENCE 

The rusting of iron and the decay of vegetation are il- 
lustrations of oxidation. Why are these not commonly con- 
sidered cases of combustion ? 

3. Into an evaporating dish put a teaspoonful of gasoline. 
Bring to it a lighted splinter, and observe. 

Half fill another dish with kerosene, and test in like man- 
ner. Pour out all but a little of the kerosene and warm 
slowly what is left, testing frequently with a lighted splinter 
held just above the dish. What is the nature of flame? 

4. Light a candle. After a moment extinguish it, and 
immediately hold a lighted match just above the wick. 
Repeat several times, noting whether the wick can be ig- 
nited when the flame is some distance from it. How is this 
possible? What is the " flame" of a candle? What con- 
ditions are necessary for any flame? Name in order the 
steps in the ignition and continued combustion of a candle. 

5. Note the parts of a candle flame distinguished by color, 
and state their relation to the wick and to one another. Hold 

in the candle flame just above the wick the 
wood part of a match, withdrawing it after 
a moment to observe the positions of the 
charred parts with reference to the parts of 
the flame. Repeat several times, and infer 
concerning the interior of the flame. 
Fig. 6. — Parts of Press down over the candle flame nearly 

a candle flame. pi- ttt . , 

to the wick a sheet or white paper. With- 
draw it before the paper ignites, and observe the form of 
the charred portion. From several such attempts reach a 
conclusion as to the interior of the flame. 

Describe the parts of a candle flame as to nature and form. 




HEAT IN RELATION TO THE HUMAN BODY 11 

Explain the persistence (a) of the inner cone; (b) of the 
wick. 

6. Put the tip of a blowpipe into the inner cone of the 
candle flame, and by repeated trials cause the yellow part 
of the flame to very nearly disappear. What is the explana- 
tion of this change ? 

Hold the inner edge of an evaporating dish in this blow- 
pipe flame for a moment. Then hold another part of its 
surface in the candle flame. Observe any deposit on the 
dish in either case, and state its probable nature and source. 
Account for any variation in amount of the deposit in the 
two cases. Give an explanation of the light-giving power of 
the yellow part of the candle flame. 

7. Hold a clean dry bottle mouth down over a burning 
candle, and look for any moisture (water) on the sides of 
the bottle. Assuming that there is no water in the candle 
material, account for its appearance in the bottle. 

Observe a lighted splinter when it is put down into the 
bottle that has just been held over the candle flame, and 
explain the results. Set the bottle aside with a cover on it. 
When it is cold put into it a little limewater (10 c.c.) and 
shake. Any milky appearance of the limewater is due to 
the presence in the bottle of the gas carbon dioxide. 

8. Breathe through a glass tube into limewater in a test 
tube till a marked change occurs in the appearance of the 
limewater. What is the significance of this change ? What 
is indicated concerning processes within the body ? Whence 
is derived (a) the oxygen ; (b) the carbon ? In what re- 
spects does this oxidation within the body differ from or- 
dinary combustion? What significance has the fact that 



12 LABORATORY LESSONS IN GENERAL SCIENCE 

people in cold weather and in cold climates crave fatty 
foods? What is the normal temperature of the body? 

9. What are signs of lack of oxygen in the air that we 
breathe? By what means other than respiration may the 
air of our rooms be robbed of its oxygen? What provision 
does nature make to rid the air of carbon dioxide and restore 
oxygen to it ? 

VENTILATION 

1. Over two holes cut in the cover of an empty cigar box 
sert chimneys made air-tight at the bottom with vaseline. 
Have a bit of candle burning within one of the chimneys. 
Test for air currents at the tops of the chimneys by means 
of smoke from an extinguished match (or joss stick). Ex- 
plain in full what is discovered. 

What is true of the relative temperatures of the air in the 
two chimneys? In what other respects is the air above 
the candle unlike that in the other chimney? How was 
the air in the box affected because of the differences in 
temperature of the air in the two chimneys ? 

2. Why does the air of a schoolroom need to be continu- 
ously changed? At what season of the year is it neces- 
sary to give especial attention to this matter ? What eco- 
nomic considerations are to be taken into account in the 
ventilation of rooms in winter? What danger to health 
must be avoided? What change should the outside air in 
winter undergo before it is allowed to spread through an 
occupied room ? By what means other than that employed 
above might a current of air be maintained through the rooms 
of a building ? 



HEAT IN RELATION TO THE HUMAN BODY 13 



3. To secure desired changes of air in rooms of a build- 
ing provided with air-shafts, but without fans or other 
devices for forcing air into and out of rooms, what must 
be true at all times (a) of the relative temperatures of 
air at inlet and outlet ; (6) of the place for outlet that no 
warmed air escape without yielding for use its oxygen; 
(c) of the place of inlet that the cold air be warmed 
before it spreads through the room? What devices may 
be employed to break up an incoming cold air current and 
divert it upward? 

4. Hold a lighted candle (a) at the top of an open door- 
way; (b) down at the floor. Repeat the tests at narrow 
openings made by lower- 
ing the upper sash of a 
window, and raising the 
lower one. What ob- 
jections are there to ven- 
tilating rooms in either 
of these ways in cold 
weather ? 

5. Why is there need 
of special attention to 
the ventilation of our 
sleeping rooms ? How 
may this be provided 
even in the coldest 
weather? What are some of the results of inattention to 
ventilation of sleeping rooms ? What is the change in com- 
position of the air of a room where gas lights or oil stoves 
are kept burning? 




Fig. 7. — A victim of oxygen starvation 
becomes an easy prey for tuberculosis 
or other germ diseases. 



14 LABORATORY LESSONS IN GENERAL SCIENCE 



6. That the lungs may be able to perform their work 
(function) well, and make use of the available oxygen, in 
what condition must the tissues of all their parts be ? What 
in general are the two requisites for the healthy condition of 
any organ of the body? Why is a diseased state of the 
lungs less likely in a person who leads an active out-of-door 
life? What is tuberculosis of the lungs? 

RESPIRATION 

1. With the hands held firmly against the chest walls 
at the sides, take several deep breaths. Describe in a 
general way what motions of the walls are noted. What 
name is given that part of the breathing process in which 
air (a) goes into the lungs ; (b) is expelled from the lungs ? 

2. Name in order the principal passage- 
ways through which air goes on its way to 
the lungs. 

3. Compare the movements of air pass- 
ing into and out of the chest during respires 

tion, and into and 
out of an accordion 
while being played. 

4. Sitting erect 
and in a comfort- 
able position, count 
the number of ex- 
halations per minute 
in your breathing. 
5. Fill a gallon jug with water, and close with a stopper. 
Let the teacher invert the jug, and with its mouth under 




Fig. 8. — Using a spirometer to test lung capacity. 



HEAT IN RELATION TO THE HUMAN BODY 15 

water in a tub or sink remove the stopper. Holding the 
inverted jug tipped sufficiently, let one end of a rubber tube 
be put up through the neck of the jug. Have some one 
of the class fill his lungs to their utmost capacity, and then 
through the tube force out into the jug as far as possible all 
air from the lungs, withdrawing the end of the tube from 
the jug before taking the other end from the mouth. 

Keep the mouth of the jug under water and replace the 
stopper to retain in the jug all the water not displaced by 
the exhaled air. Remove the jug from the water, set it right 
side up, and by use of a graduate ascertain the volume of 
air expelled from the lungs by measuring the quantity of 
water needed to refill the jug. 1 [Lung capacity is tested 
most satisfactorily by use of a spirometer.] 

6. In like manner, and as average of several trials by 
the same person, determine the volume of a natural (not 
forced) exhalation. 

7. From the results above, calculate what per cent of 
the air capacity of the lungs was used in once breathing. 
Infer a good purpose served (a) by an occasional long, deep 
breath ; (6) by not having the lungs emptied of all air at 
every breath. 

8. From the data above calculate the volume of air taken 
into the lungs (a) per minute; (b) per hour. About one 
fifth of this is oxygen. 

Calculate how long it would take the individuals present 
in the room to breathe as much air as the room contains, 
using the same air but once. 

1 1000 c.c. (1 liter) is equivalent to about 64 cubic inches. 



16 LABORATORY LESSONS IN GENERAL SCIENCE 

9. Close the lips tight, take a deep breath, hold the 
nostrils tight shut with thumb and finger, and note the 
length of time you can refrain from exhaling. 

10. Expel the air from the lungs as fully as possible, 
and note how long you can keep from inhaling. Account 
for its being a shorter period than for exhaling. 

What would be the result of shutting off from the lungs 
all air supply for even so short a time as 10 or 15 minutes? 
What is the real nature of death by drowning? 

11. State so far as known to you the steps taken to re- 
suscitate (restore to life) a drowned person, together with 
the purpose of each step. What is meant by asphyxiation 
(as-fik-si-a'shun) ? 

THE HUMAN BODY AS AN ENGINE 

1. From a general knowledge of steam engines, state (a) 
the purpose of burning fuel in the fire box ; (6) the need of 
a draft. 

2. What is true of the relative amount of fuel needed 
when the engine is (a) working full capacity, and when 
more or less inactive ; (b) well protected from the cold, and 
when left exposed ? By what means is water changed into 
steam? What then is there in the steam that does the 
work for which the engine is employed ? 

3. What will be the effect (a) if the fuel supply is exhausted ; 
(b) if the draft is shut off for any considerable time ? 

What is true of the power of the steam engine when there 
is insufficient heat? What is the significance of escaping 
steam when a locomotive is not at work ? 



HEAT IN RELATION TO THE HUMAN BODY 17 

4. Why may death result if the temperature of a per- 
son's body continues for some time several degrees below 
normal? What is evidence of a superabundance of energy 
in a person ? 

5. What in our bodies corresponds to fuel for the engine ? 
Name several kinds of body fuels. Before these become 
available as fuel what changes must they undergo in the 
body? 

6. What part in this heat production has respiration? 
Where does the oxidizing action go on, and where in the body 
is heat liberated ? What part in all this has the circulation 
of the blood ? 

7. Recall the effects of vigorous exercise, whether of work 
or play, upon (a) the rapidity and volume of breathing ; (b) 
the rate of pulse beat; (c) the temperature of body. Ex- 
plain the relationship of these conditions. 

8. How much of our thought and attention do the pro- 
cesses of digestion, respiration, and circulation of blood 
commonly require? In case we did need to give these ac- 
tivities our attention, how would it affect us in the affairs of 
life? 

REGULATION OF BODY TEMPERATURE 

1. Dip the hand into water ; then wave it back and forth 
in the air and note the sensation. Hasten the evaporation 
by fanning, and observe any difference in the sensation. 
Whence is derived part at least of the heat necessary to 
vaporize the liquid? What is true of the temperature of 
the body when perspiration vaporizes on the skin ? 



18 LABORATORY LESSONS IN GENERAL SCIENCE 

2. What is the nature of perspiration ? What is meant 
by a secretion? 

3. What relation is commonly noted between the tem- 
perature of the body and the amount of perspiration ? 

4. State clearly and somewhat in detail the natural pro- 
vision that has been made to avoid excessive temperatures 
in the body. What is the apparent relationship between 
excess of heat in the body, amount of perspiration, and the 
disposal of this heat by vaporization ? 

5. What care should be given the skin that it may be 
in condition to regulate body temperature? How do we 
protect the body from sudden extreme temperature changes ? 
Why is there danger in wearing wet clothing ? 

6. In what ways has man provided against excessive loss 
of body heat by radiation to the surrounding air? Why is 
there risk to health by exposure of neck and chest in cold 
weather? Why should a person wear rubbers in wet 
weather ? 

7. What is likely to be true of the temperature in any 
organ or part of the body (a) where the blood vessels are 
continuously gorged with blood; (6) where for any cause 
excessive oxidation is taking place? How is the weight of 
the body affected by a combination of excessive oxidation 
and impaired digestion ? 



III. HEALTH AND WELL-BEING 

KEEPING WELL 

1. When one is seriously sick, what are some of the 
usual expenses of the sickness ? 

2. In a general way what constitutes the difference be- 
tween being sick and being well — between having good 
health and being diseased ? 

3. What may commonly be expected sooner or later as 
a result of an unhealthy or diseased condition of the body ? 

4. What good purpose is served by pain? What com- 
monly follows neglect to heed the first warnings of pain? 

5. When a physician is called in case of any illness, 
what will he seek to discover before prescribing any treat- 
ment? Why? 

6. What constitutes the best course for anyone to follow, 
whether under direction of a physician or not, as regards 
air, food, drink, sleep, exercise? In what respects other 
than drink does one need to be "temperate" ? 

7. What is commonly true of the body temperature as 
a result of serious illness, or of conditions in the body likely 
to cause sickness? Why is it well to have for family use 
a thermometer such as physicians carry? 

8. In what sense may it be said that some people culti- 
vate sickness rather than health? 

19 



20 LABORATORY LESSONS IN GENERAL SCIENCE 




Fig. 9. — This position makes impossible the full 
deep breathing necessary for health. 



9. What effect 
on the return of 
blood to the heart 
has muscular exer- 
cise, whether work 
or play? What in 
the appearance of a 
person is evidence 
of a sluggish circu- 
lation ? 

10. Why is work 
a blessing rather 
than a curse to 
man? When does 
it become a curse? 



INFECTION 

1. It is known that the cause of many of the diseases 
that are "catching" is the introduction into the human body 
of living organisms so minute as to 
be seen only when examined under 
the microscope. These are very 
properly called microorganisms, or 
microbes, or simply germs. Many of 
these are minute forms of plant life 
known by the name of bacteria. Once 
lodged within the body these germs, 
under conditions favorable to their 
grow r th, will multiply in number at a truly marvelous rate, 
and directly or indirectly bring about a diseased condition in 
the patient. What is the meaning of the term bacteriology? 




Fig. 10. — Size of bacteria 
relative to that of the 
point of a fine needle, 
both greatly magnified. 



HEALTH AND WELL-BEING 21 

The microscope is to the bacteriologist very much what 
the telescope and its accessories are to the astronomer. As- 
certain the literal meaning of the terms- (a) microscope; (6) 
telescope. 

2. Fortunately the number of kinds of germs which cause 
disease in persons is relatively small. The symptoms of 
the ailment and the degree of danger to the life of the patient 
vary with the kind of germ, its vigor, and the state of 
health of the person. In some cases the development of 
the germs after their introduction into the body can be 
checked or prevented ; in other cases the disease must run 
a course dependent upon the life changes through which 
the germ passes. In such cases whether the patient lives 
or not depends in large measure upon his powers of endur- 
ance. Explain the weakness of body incident to long-con- 
tinued sickness. Aside from feeling a need for it, why is it 
better when sick to keep quiet, even remaining in bed ? 

3. When persons recover from a germ disease the sys- 
tem often seems to remain for a considerable period of time 
in a condition unfavorable to any new development of the 
kind of germs that caused that disease. Ill effects may not 
be experienced from them for a long time. One is then 
said to be immune to that particular disease. 

A like condition is often brought about under direction of 
a physician by processes of inoculation, or vaccination. There 
is introduced into the system a specially prepared virus, or 
serum. This causes a mild form of the ailment, and leaves 
the patient for a time immune to any severe attack, and pos- 
sibly to any attack at all of that disease. 

The life products of the disease germs within the human 



22 LABORATORY LESSONS IN GENERAL SCIENCE 



body often act on the tissues as poisons, or toxins. They are 
destructive of the life of the tissues. Remedies that coun- 
teract the effects of these products, or that prevent their 
formation by preventing multiplication of the germs, are 
called anti-toxins. 

To secure immunity against what diseases are persons 
vaccinated? For what ones are serums administered? 

4. When the skin on the body is cut or torn, germs 
may find lodgment in the wound. Their development and 
multiplication may cause an unnatural secretion called pus. 
This pus, and the toxins it contains, when absorbed into the 
blood and circulated throughout the system may cause 
blood poisoning. Aside from the desire to relieve pain 
caused by pressure, why is a physician or surgeon often 

employed to lance any seri- 
ous swelling, e.g., a boil? 
Various substances, applied 
promptly to wounds and to 
bandages used, either destroy 
the germs or make conditions 
unfavorable to their growth 
and development. Such sub- 
stances are called antiseptics. 
(Septic has reference to pu- 
Modern surgery owes much of 
its success to the use of antiseptics. Where the tissues of a 
wound are kept free from germs and in a healthy state, 
rapid healing is possible. 

The absolute destruction of the life of these germs, whether 
by action of chemicals or by high temperatures, is called 
sterilization. The surgeon is exceedingly particular in all 




Fig. 11. — Sterilization by boiling. 

trefaction of animal tissue.) 



HEALTH AND WELL-BEING 23 

operations that his instruments, his person, and his clothing 
are sterilized. 

"First aid" treatment for the wounded, whether on the 
battlefield or elsewhere, seeks by the use of antiseptic treat- 
ments at once, and before removal to any hospital, to pre- 
vent the infection of the wound, i.e., the introduction into 
it of germs. What is the explanation of pus formation in a 
wound? What in general may be considered one of the 
chief functions of the skin? 

5. In what ways other than through breaks in this 
protective covering of the body may germs be introduced 
within the body? In what several ways may the presence 
of the long-lived typhoid germs be accounted for (a) in the 
water from wells and from city water systems ; (6) in milk 
for family use and for sale ; (c) in fruits purchased in market 
and vegetables gathered in a home garden ? What part are 
flies believed to play in the spread of typhoid ? 

6. Where germs causing disease are communicated by 
contact with infected persons or their clothing, the disease 
is spoken of as contagious. Many communicable dis- 
eases may be classed as both contagious and infectious. 
What precautions are usually enforced to prevent the spread 
of smallpox and diphtheria (dif-the'ri-a) as contagious dis- 
eases ? In cities and towns, who has the responsibility and 
the power to enforce regulations to this end? Why are 
the periods of quarantine for different contagious diseases of 
different lengths? What does the physician do to avoid 
carrying contagious disease ? 

7. In order to avoid infection various means are employed 
to destroy the germs likely to be present in the clothing, and 



24 LABORATORY LESSONS IN GENERAL SCIENCE 

in the waste matter of the sick room. What exact meaning 
have the words disinfect and disinfection? What is a 
disinfectant? What is the safest course to pursue with re- 
gard to clothes used by a sick person, and all bedding and 
furnishings of small value? In case infected clothing is 
not destroyed, how is it to be cared for until it is washed? 
What disinfectant may be put into the wash water? Why 
should the cover of the wash boiler be kept on while the 
clothes are being boiled? 

8. In case a room is to be disinfected, what kind of dis- 
infectants may be used to insure the destruction of germs 
lodged upon walls and furniture, and within blankets, heavy 
clothing, and carpets? 

State just how to proceed in this disinfecting process. 
How much disinfectant should be used, and for how long a 
time? 

9. How should dishes from the sick room be treated? 
How should all waste matter from the sick room be treated 
before disposing of it in sewer or cesspool ? 

10. What measures may be taken for the protection of 
the public health where through ignorance or carelessness a 
family fails to observe proper precautions? What can be 
done when there is willful neglect by a family to carry out 
the directions of the physician and nurse? 

SANITATION 

1. When people are sick every effort should, of course, be 
made for their complete recovery. But it is better for them 
as individuals, and better for any community, to strive to 
prevent sickness and disease. Aside from the suffering and 



HEALTH AND WELL-BEING 25 

hardship involved, sickness is wasteful. No one can afford 
it. About what is the expense in bills for doctor, medi- 




Fig. 12. — The school doctor. 



cines, and nurse during a month's serious illness? Name 
several other ways in which there is loss through sickness. 

Ascertain the significance of the terms sanitary, sanitation, 
insanitary. 



26 LABORATORY LESSONS IN GENERAL SCIENCE 

Cleanliness and wholesomeness should characterize every 
part in the process of food preparation. Because it is im- 
possible for consumers to know the conditions under which 
the foodstuffs sold in market have been prepared, and 
whether these foodstuffs are of the quality and weight 
represented to purchasers, there has arisen need of Pure 
Food Laws and of provisions for their enforcement. Why 
is the need for sanitary precautions in handling food supplies 
imperative ? What conditions must be observed in the care 
of food in our homes? 

2. Explain why sleeping in small closed rooms in winter, 
or working in overcrowded rooms not properly ventilated, 
is insanitary, aside from the danger of oxygen starvation. 

3. Why is it that open sewers and rotting piles of garbage 
and stable refuse are insanitary? What is the common 
means of protection of our homes from the flies that breed 
in such places? What is a better course? Why is there a 
menace to health in the exposure of foodstuffs to dust blown 
about on city streets? What precautions should be taken 
against infection with malarial germs? Why are not all 
mosquito bites equally dangerous? 

4. How may ice become a carrier of infection? What 
care should be exercised (a) where food is kept in refriger- 
ators ; (6) in the use of ice for cold drinks ? Why is it that 
food does not spoil so soon when kept cold in a refrigerator ? 

5. Why is there greater need of attention to sanitary 
measures now than formerly? What is the penalty of 
carelessness and ignorance in these matters ? Are cases of 
sickness made more dangerous because of a better knowledge 
of the nature of infection? What on the other hand is 



HEALTH AND WELL-BEING 



27 



gained by reason of such knowledge? What results are 
sought in a widespread enlightenment of people in matters of 
health? How many people have need of such knowledge? 
Why is it an even greater need than a knowledge of how to 
cure illness? 

THE WATER SUPPLY AND HEALTH 

1. Account for the supply of water (a) in shallow wells ; 
(6) in very deep ones. How is the caving in of dug wells 
commonly prevented? How is surface water to be kept 
from running into such wells ? Why should there be a tight- 
fitting cover over the well? 

2. Describe the general character of the upper layers of 
the earth's crust that makes possible an ample water supply 




Fig. 13. — Conditions for wells. 



when pipes are driven through them. Illustrate by diagram 
the conditions that make artesian wells possible. How is 
the heat of certain springs and of geysers accounted for? 

3. Discuss the necessity for care in locating wells near 
dwellings and outbuildings. What element of danger is 
there from cesspools, drains, and leaky sewers even when 



28 LABORATORY LESSONS IN GENERAL SCIENCE 

the well is on higher ground? What special dangers are 
there in the use of well water in towns? 

4. Describe somewhat in detail the construction of 
cisterns. What difficulties are experienced in providing for 
a water supply by storage in cisterns? What advantages 
are there in the use of cistern water rather than well water ? 
State objections to its use for drinking and cooking. Aside 
from the possibility of disease germs in it, why may drink- 
ing cistern water cause sickness? 

5. By use of a diagram show the construction of a 
cistern having a filtering wall of porous brick, and indicate 
suitable places of inlet and outlet for the water. What 
precautions should be taken to keep cistern waters free 
from dust and from organic matter? What difficulties 
are there in filtering rainwater as it goes into the cistern? 
What conditions in a city usually make the use of cisterns 
impossible ? 

6. Describe the action of the "chain pump" as a means 
for aerating cistern waters. Explain the nature of the 
chemical change thus accomplished in the water. Account 
for the odor and taste of cistern water. 

7. Tell something about an air-pressure system for 
supplying water to all parts of a house from a cistern. 

8. State the source of the water supply of your city. 
Describe the manner of its storage and distribution. What 
is the cost of water to a consumer? What protection has 
this water supply from contamination? What means are 
employed, if any, for its purification? 

9. What danger is there in the use of water from streams ? 
What advantages may there be ? What is generally true of 



HEALTH AND WELL-BEING 



29 



the purity of spring waters ? By use of a diagram show how 
springs arise. 

10. Where the water supply of a city is drawn from a river 
into large storage reservoirs, (a) what provision is made for 
filtering on a large scale ; (b) what means other than filtering 
is employed to rid the water of suspended matter ; (c) what 
method is employed on a large scale for the aeration of 
stored waters? 

11. Where there is reason to suspect the purity of a 
water supply, what wise precaution should be followed in 
the home to avoid danger of infection from the water ? How 
may it be determined whether or not there are "germs" 
in the water supply? How is it learned what particular 
disease germs are present? 



GENERAL HEALTH PROBLEMS 

1. Name several conditions wholly under the control of 
an individual that contribute to the public health. Men- 
tion others, present especially 

in towns, that are not wholly 
controlled by him. 

2. Describe in a general 
way how infection occurs. Dis- 
tinguish between infection and 
contagion. What relation has 
one's general state of health to 
"taking" a disease? What is 

the physiological explanation FlG . 14 .- Sunshine as a 

of this ? disinfectant. 




30 LABORATORY LESSONS IN GENERAL SCIENCE 



3. Write briefly the main features of the life history of 
mosquitoes. What is one way to destroy them in great 
numbers, and to keep rid of them in an infested region? 
What more may be necessary? What part is played by 
one kind of mosquito in the spread of yellow fever ? What 
must be done in order to prevent the spread of this disease ? 

4. Relate somewhat at length the life history of the 
common house fly. At what rate do flies multiply under 
favorable conditions ? What conditions are favorable ? What 

is the procedure in a warfare 
for their extermination ? 

5. What is the manner of 
disposal of garbage in your 
city ? In what respects is there 
menace to health in such a 
course ? What better ways are 
employed by other cities? 

6. In the installation of a 
seivage system for a town, what 
must be provided for moving 

Fig. 15. — The house fly (magni- 1 • i i i i 

fled). Note the hairs on legs the waste material through the 
and body. sewers ? 

7. What is an estimated amount of property losses 
through the depredations of rats every year? How are 
buildings made rat proof? Rats are charged with being 
agents in the spread of the dreaded Asiatic plague. How 
is this believed to occur? What is done to exterminate 
them in a city where the plague has obtained a foothold? 

8. Why do we have health ordinances, and health officials ? 
What are the duties of a Board of Health? Why is there 




HEALTH AND WELL-BEING 31 

need of a well-informed citizenship in matters of public 
health ? What can the individual citizen do to aid in main- 
taining public health? 

9. Mention one or more instances known to you of the 
enforcement of pure food laws. What are the duties of 
State Food Inspectors generally? How may violations of 
the pure food laws be stopped? What are desirable health 
regulations in the sale (a) of milk; (b) of fruits and vege- 
tables ? 

10. Explain the preservation of foodstuffs (a) by employ- 
ment of low temperatures, as in cold storage; (b) by use of 
high temperatures, as in sterilization of milk and in canning 
foodstuffs; (c) by use of salt, vinegar, sugar, etc., in the 
pickling processes; (d) by use of smoke in the curing of 
meats. Why then is it considered so harmful to put 
formaldehyde in milk, boric acid in meats, and salicylic 
(sal-i-sil'ik) acid in fruit products in order to preserve them? 

11. What are the advantages in cold storage of perish- 
able foodstuffs? Why is there need for public control of 
these storehouses? 

12. What revolution has been wrought in the problem of 
food supply by the rise of the canning industry? Why is 
the control of this industry in the interests of public health 
a comparatively easy problem? 

LIFE, GROWTH, REST AND RECREATION 

1. How can we tell whether a tree is dead or alive? In 
what ways can it be decided whether an animal is dead or 
not? In general, how may plants be distinguished from 
animals? The protoplasm (pro'to-plazm) of the cells in 



32 LABORATORY LESSONS IN GENERAL SCIENCE 

plants and animals is the material that is alive. Just what 
this "life" may be, making the difference between living 
and dead tissues, remains unknown to scientists. 

2. Growth of the tissues is commonly accomplished by 
the subdivision of living cells, apparently from causes 
(activities) wholly within the cell itself. These new cells 
are like the original cell, and are in turn capable of sub- 
division. In the case of the microscopic plants known as 



Fig. 16. — Successive stages in the subdivision of a cell. 

bacteria, subdivision under favorable conditions is said to 
occur as frequently as every twenty or thirty minutes. 
Calculate in round numbers how many of these one-celled 
bacteria could result in twenty-four hours from a single cell 
where subdivision of every cell occurred every half hour. 

3. In the higher orders of plants, and in animals, the for- 
mation of a more complex cell structure is far slower than 
this, and in active animals like man a fairly even balance is 
maintained throughout much of one's life between increase 
in new cells and the destruction of others. Why may any 
considerable loss in weight during middle life, or failure 
during youth to increase somewhat regularly in weight, 
be a cause for concern ? 

4. Activity in some form is an accompaniment as well as 
an evidence of life. A low degree of physical or mental 
activity is oftentimes evidence of a lack of sound conditions 



HEALTH AND WELL-BEING 



33 



of body. State the relation of physical vigor (a) to an in- 
sufficient supply of nourishing food; (b) to poor digestion; 
(c) to imperfect assimilation; (d) to lack of pure air, suffi- 
cient sleep, and suitable exercise. 

5. In what one organ of the body are largely centered 
the activities upon which the mental processes depend ? In 




Fig. 17. — Recreation at school. 

general how much does its development depend upon mus- 
cular prowess? Muscular exercises and physical training 
should be directed chiefly to what ends ? What is the argu- 
ment for school athletics (a) where all pupils have opportu- 
nity to engage in them ; (6) where but a few are trained whose 



34 LABORATORY LESSONS LN GENERAL SCIENCE 

contests are to be witnessed but not participated in by the 
school body at large? What evils in matters of health re- 
sult from over-training and excessive efforts? Why is it 
that change in occupation may afford refreshment? How 
is it that activities employing both hand and head are often 
less tiresome than either mental or manual labor alone? 

STIMULANTS AND NARCOTICS 

1. Stimulating trade, stimulating political interest, 
stimulating public opinion, are expressions frequently heard. 
What is there common in their meaning ? 

2. In what ways may a shower bath, or a sponge bath, 
have a stimulating effect upon the body? What effect of 
hot drinks taken into the stomach warrants speaking of 
them as stimulants? Why is the alcohol of various drinks 
and medical preparations a stimulant for the human body? 

3. When a horse is stimulated under vigorous use of 
the whip to make unnatural efforts in moving heavy loads, 
what harm to the animal is likely from these efforts ? What 
harm to the organs of the human body will probably result 
from the use of alcoholic drinks even in small quantities? 

4. What is true of the number of people who begin the 
use of alcoholic liquors and become addicted to the drink 
habit, after they are thirty years old? What significance 
has this ? Why is it that young men beginning the use of 
intoxicating drinks are likely to become drunkards though 
not planning to do so? 

5. Name some advantages to a person in having formed 
the habit of doing what is for his own welfare. What is 
the explanation of habit as a condition of the body? In 



HEALTH AND WELLr-BEING 35 

what sense is alcoholism a disease ? Why do so few recover 
from it? 

6. Apart from the use of alcoholic drinks what in general 
constitutes a temperate manner of life ? What does temper- 
ate living involve as to (a) kind and quantity of food taken ; 
(b) sleep; (c) amusements and recreations? 

7. In the building up of the body tissues what is the 
food value of tea and coffee ? In what respects may their 
use become a serious menace to health? 

8. What is meant by narcotics ? Name several. Under 
what circumstances are narcotics a blessing to mankind? 
When do they become a curse? Why are liquids contain- 
ing alcohol included among the narcotics? 

9. What is meant by the drug habit? Why is it so 
seldom overcome? How is it that anyone becomes a 
victim of the drug habit ? Why is instruction in the terrible 
results of the habitual use of drugs necessary in schools? 
Under whose direction only should drugs ever be taken? 
Why so ? Why are there such stringent regulations for the 
sale of opium and its compounds, and of other narcotics ? 

10. The claim that one's nerves are soothed by use of 
tobacco is confession of what fact? Give any sufficient 
reasons for learning to smoke after one is thirty years old. 
From your knowledge of the growth of the body by cell- 
division, and of the nature of the protoplasm of the cells, 
account for the stunting of body and mind in boys from ex- 
cessive use of tobacco. 

11. Why are "soothing sirups" given to infants? 
Judging from their effects what must they contain? What 



36 LABORATORY LESSONS IN GENERAL SCIENCE 

is a common constituent of them? What harmful effects 
may follow their use with infants ? 

12. What alone constitutes a cure for any ailment? 
Wherein lies the efficacy in general of the "cures" for head- 
ache? What is the objection to an indiscriminate use of 
headache powders? 

13. Preliminary to all medical treatment worthy of the 
name, and indispensable before administering any remedies, 
is an understanding of the cause of the ailment — a correct 
diagnosis of the case. Without such knowledge what ex- 
pectation can there be that the cause of the sickness will 
be removed and health restored? In the use of "patent 
medicines/' what recognition is there of any need to deter- 
mine the cause of the ailment ? How much consideration 
is given to the manner of life of the patient? 

14. What is true of the competency of most people, 
young or old, to diagnose ailments and prescribe treatments 
for themselves ? To what extent ordinarily is there any pro- 
tection to purchasers in having the names of the ingredients 
of any patent or proprietary medicine printed on the label ? 
What is true of the knowledge of persons generally of the 
effects of these ingredients? What explanation is there 
for the widespread use of patent medicines ? 

GENERAL SCIENCE, AND RIGHT LIVING 

1. Under all normal conditions of living what is true of 
the growth of children day by day and year by year in 
height, weight, and strength? In these respects at about 
what age does a boy become a man f 



HEALTH AND WELL-BEING 37 

2. In order to grow in body day by day, increasing in 
weight and in strength, what are some of the conditions 
necessary to be observed? For intellectual growth, and 
for increase in mental capability, what constitutes (a) the 
needed food; (b) the exercise required? At about what 
ages does a person attain full measure of mental powers? 

3. It may be assumed as true that something more vital 
than age or stature marks the distinction between a man and 
a boy. The change from childhood to manhood or woman- 
hood may very properly be measured by an ability to direct 
one's self aright in what is thought and said and done. In 
that case what length of time in a general way is required 
for a child to grow to be a man or a woman ? What are some 
suitable tests to determine whether a boy is growing to be a 
man or not ? How much change in this respect is likely to 
be noted in any one day or in several days ? 

4. The failure of a person to do what he knows should 
be done by him may be considered evidence of what stage 
of growth for him? What in a large measure aids anyone 
to decide whether any particular act in life is right or wrong 
for him ? For how many years may one keep growing in a 
mastery of himself so that he does what he ought, and does 
it without being told to do it ? If one at all times seeks to 
do right things, how much need will there be for him to 
give attention to what ought not to be done ? 



IV. MATTER AND FORCE 

SOME PROPERTIES OF MATTER, AND CHANGES IN 
MATTER DUE TO FORCE 

1. Into a test tube already filled with water, attempt to 
put considerably more water without causing any over- 
flow. What constitutes a satisfactory " explanation " of 
the inability to do this? 

Our knowledge of the existence of the water, and of the 
existence of any other portion of matter, involves the fact 
that they "occupy space, " and that no two bodies can occupy 
the same space at the same time. To say that matter is 
that which occupies space tells what matter is by naming a 
distinguishing characteristic. This does not in any way 
imply that scientists themselves have any complete knowl- 
edge of the real nature of matter, nor does it mean that there 
may not exist that which takes up no room, and is there- 
fore not matter. Indeed, the study of Physics is quite as 
much concerned with that which as force (the cause of changes 
in matter) has itself no material existence. 

2. Every portion of matter extends outward from a point 
within the body in three different directions, giving £o the 
body its dimensions of length, breadth, and thickness. Ex- 
tension, impenetrability, form, size, and density are closely 
related properties of matter. Give the definitions for 
each. 

3. Push a book lying upon the table, and note that it 
can be moved — that it has mobility. Now let it alone, 

38 



MATTER AND FORCE 39 

and see if it moves of itself. What is a reasonable inference 
concerning the ability of a body to move itself? When a 
body is found moving, what may be assumed as cause of its 
motion ? [In the study of Physics phenomena due to any 
" life " in matter are not considered. Bodies are supposed 
to be lifeless.] 

Hold a pencil out at arm's length, and then let go of it. 
When does it stop falling? Infer if it could have stopped 
itself when falling, all other bodies being out of the way. 
The tendency of a body when in motion to continue moving, 
and the inability of a body to set itself in motion, constitute 
together the characteristic of all matter known as inertia. 
Formulate a definition for this property. 

4. Stretch a rubber eraser ; then bend it, and then twist it. 
What holds the particles {molecules) of the eraser together, 
resisting their separation? Are the parts held together 
alike in nature, or unlike? Define cohesion. What force 
was applied in these cases to change the form of the eraser ? 
Where a body subjected to any force has its form changed 
rather than its position, i.e., where it resists being moved, 
it is said to be under strain. Where the body resists being 
pulled apart it is under tension; when twisted, it suffers 
torsion; when bent, flexion. When the parts of a body 
are pressed together it is said to be under a strain of com- 
pression. Formulate definitions for these four forms of 
strain. 

The force which causes any of these forms of strain in a 
body is spoken of as a stress, regardless of what force it may 
be. Stress and strain are thus correlative terms, and the 
use of one of them implies the other. 



40 LABORATORY LESSONS IN GENERAL SCIENCE 

5. When a rubber eraser is under any strain, what marked 
tendency as to form becomes at once apparent upon removal 
of the stress? To what is this recovery of form to be at- 
tributed? The property of matter thus made manifest is 
known as elasticity. Formulate a definition for it, being 
careful v to include mention of the force upon which this 
recovery of form depends. 

Gases have no form of their own, but when released from 
pressure they regain the volume (size) they had before they 
were compressed. Now re- word the definition for elasticity 
to make it include the more or less complete recovery of 
both size and form in bodies when any stress upon them is 
removed. 

6. Try to break a piece of copper or iron wire by pulling 
upon it, by bending it, and by twisting it. What resists 
the efforts made? Say the wire has tenacity. In what 
class of bodies (or what state of matter) must tenacity be 
lacking? Define tenacity as a specific (not general) prop- 
erty of matter. 



V. WATER, AND ITS USES 

SOME PROPERTIES OF WATER 

1. Which of all the things needed to keep us alive causes 
suffering most quickly when withheld? Which next? 
What is the price we need to pay ordinarily for either ? How 
do you account for this ? 

2. Taste water from different glasses, one glass having 
in it salt, another sugar, another vinegar. Then taste of 
pure water. What property of pure water is shown? 

3. Smell ammonia water cautiously; then pure water. 
Name another property of pure water. 

4. Look at a pencil through glass. Put the pencil in 
water, and look at it through water. What other property 
of water is shown? Explain the muddy appearance of 
some rivers. 

5. Name several substances that dissolve readily in 
water. Name a few that do not. What solvent power has 
water as compared with other liquids? If water did not 
dissolve most substances, what would be true (a) of the 
digestibility of our foodstuffs ; (b) of their taste ? Name 
some substances unsuited for food because they are so slow 
to dissolve. 

6. Pour water into dishes of different shapes, and state 
the form taken by the water in every case. Why is this? 
Make a distinction between solid and liquid states of 
matter. 

41 



42 LABORATORY LESSONS IN GENERAL SCIENCE 

Grasp a handful of sand. Try to do the same with water, 
and explain the difference in results. Explain why liquids 
at rest have a smooth upper surface rather than a rough 
heaped-up form. 

VAPORIZATION AND CONDENSATION 

1. What change occurs in the quantity of water (a) when 
a little is left in an open dish exposed to the air for some 
time ; (b) when a wet piece of cloth, as a handkerchief, is 
hung up exposed to the air ? After some water has been 
boiled for a time in an open dish, what is true of the quan- 
tity of it? 

In all these cases what becomes of the water? At what 
temperatures does this change of vaporization of the water 
go on most rapidly ? Name other conditions that favor a 
rapid vaporization of water from the earth's surface. Name 
several sources whence the supply of moisture in the air is 
maintained. Whence comes the heat? 

2. Over the mouth of a test tube in which water is boil- 
ing hold an inverted wide-mouthed bottle whose sides are 
dry and cool. Describe what takes place. What relation 
is there between the processes of vaporization and con- 
densation f What causes condensation of the moisture 
present in the atmosphere? In what ways (two or more) 
does this come about? 

3. How is it that in some regions of earth a sudden and 
extreme fall in temperature may cause no precipitation 
either of rain or snow T ? What is true of the general character 
of a region, and its fitness for habitation, where the atmos- 
phere is commonly destitute of moisture ? In regions that 



WATER, AND ITS USES 



43 



are far away from large bodies of water, how do you 
account for a supply of atmospheric moisture sufficient for 
an ample rainfall? 

4. Describe the difference 
in conditions that result in 
the formation of (a) dew 
and rain ; (b) white frost and 
snow; (c) fog and cloud. 

Why is it that steam is 
visible near the mouth of 
a teakettle of boiling water 
and disappears a little far- 
ther outward? Why is 




Fig. 18. — Great cloud masses result 
from the condensation to minute 
water particles of the water vapor 
in ascending air currents. 



there no appearance of this " steam" close to the outlet? 
5. When should a gaseous form of matter be spoken of 
as a vapor rather than as a gas ? 



HEAT OF VAPORIZATION, AND OF FUSION 

1. Take frequent temperature readings as the teacher 
heats some ice cold water containing small lumps of ice. 
The water must be stirred continuously with a thermometer, 
and heated slowly till the ice is melted and the water boils. 
Record the temperature (a) at the beginning ; (b) from time 
to time while the ice is melting ; (c) during the time until 
the water boils ; (d) while the boiling water is heated more 
and more. 

2. Observe the temperature of the room as registered 
by a thermometer. Wet the bulb of the thermometer with 
alcohol (or water), and wave it back and forth in the air. 
Observe the lowest temperature it records. 



44 LABORATORY LESSONS IN GENERAL SCIENCE 

Tie one thickness of cotton cloth about the thermometer 
bulb, wet it with alcohol, and repeat the test. 

What becomes of the alcohol in both cases? Recall by 
what means the vaporization of liquids has been accom- 
plished before. Give an explanation of the thermometer 
changes. When vapors are condensed and changed to 
liquids what is true of this heat of vaporization? 

3. Into a hot iron spoon put water a little at a time, 
and observe what changes occur in the water and in the tem- 
perature of the spoon. What becomes of the heat that was 
in the metal? 

What part does vaporization play in the temperature 
of any region intensely heated by the sun during the day, as 
during our summer time? What is true of the temperature 
of land surfaces largely destitute of water when under a 
summer's sun? 

SOLUTION, ABSORPTION, DIFFUSION 

1. Make crayon marks on the blackboard, or lead 
pencil marks on paper. Why does an attempt to jar or 
shake these off not succeed? 

2. Dip a finger into water. Explain why it comes out wet. 

3. Let a stream of water from some height fall into a 
jar of water. Account for the bubbles of air in the jar. 

4. Lower into water a rough stone. Why do not all 
the air bubbles on the surface of the stone rise to the liquid 
surface ? 

5. Drop a lump of salt into some water. State what 
change occurs in it. What force that previously held the 
parts of the lump together has now been overcome ? Where 



WATER, AND ITS USES 45 

is the salt now ? Get a drop of water from any part of the 
vessel that does not have salt in it. By what are the particles 
of salt and water held together ? What apparently must be 
true of the size of the salt particles ? How is it that every 
drop of water has apparently come into contact with a 
particle of salt without the liquid having been stirred or 
heated ? 

6. Evaporate some of the salt solution to dryness. Taste 
any solid left. What is it ? Let the rest of the liquid stand 
in a covered dish till next day and see if any of the salt 
settles to the bottom. If not, why not? Try to filter out 
the salt. What is here taught of the size of the particles? 

7. Stir a little earth into a tumbler of water and let it 
stand. Explain what happens. Repeat with kerosene and 
water, and explain the result. Why does cream rise on milk? 

8. Heat gently some water in a test tube. Where does 
the air that collects on the sides of the tube come from? 
(Bubbles of steam if formed could not persist in the water 
below boiling temperature.) Explain how this air was kept 
in the water. 

9. Lay a blotter down upon a drop of ink. What is 
done to the ink by the blotter? How can this be? Since 
we say that water dissolves air, why not say that the ink 
dissolved the blotter, or the blotter dissolved the ink? 

Give a good definition for solution. 

10. Note very carefully the results as the teacher follows 
out these directions : — 

Wet the inside of a clean bottle with a little strong hy- 
drochloric acid, and set the bottle to drain, bottom up. In 
like manner (perhaps in another part of the room) wet 



46 LABORATORY LESSONS IN GENERAL SCIENCE 

another bottle inside with strong ammonia water and let it 
drain. 

Both these liquids are solutions of gases in water. The 
bottles are thus made to contain in one case hydrochloric 
acid gas and in the other ammonia gas. In both cases these 
are mixed, of course, with much air. Observe any color or 
other evidence of the presence of the gases in the bottles. 

When these gases combine chemically they form particles 
of a white solid easily seen. This change can occur only 
where there is intimate contact of the gases. 

Now bring the mouths of the bottles together, holding 
both horizontally. Note the progress of the chemical 
change, and explain the mixing of the gases as the bottles 
are held in place. 1 



OSMOSIS IN THE BODY AND IN PLANTS 

Watch closely while the teacher sets up the apparatus as directed 
below, noting the results that manifest themselves through a con- 
siderable period of time afterward : — Fill with 
molasses a " diffusion bulb" that has been 
thoroughly soaked for a time in hot water, and 
insert into its mouth a close-fitting rubber stop- 
per through which has been passed a rather 
long glass tube of small bore. Twist a wire 
tight around the top of the bulb to prevent 
any leakage around the stopper. Set the bulb 
and its tube down into a bottle of water deep 

1 The striking change in the substances here is 
indeed a phenomenon. In science any change in 
matter, however familiar it may be, is considered 
a phenomenon, and is evidence of the action of some 
Fig. 19. — Osmosis force. All the changes of the preceding experiments 
apparatus for liquids. of this lesson are illustrations of phenomena. 




WATER, AND ITS USES 47 

enough to cover the bulb, and let it hang suspended there 1 till next 
day when the changes that follow will come up for discussion. 

1. Describe the change observed. What is the explana- 
tion of it? When liquids mix (intermingle) by passing 
through porous partitions by reason of their molecular 
motions alone, the phenomenon is known as osmosis. This 
term covers the mixing of gases in like manner. What 
must be true of the freedom of molecules to move about, 
that osmosis, whether of liquids or of gases, can occur? 
What is done to give solids the necessary molecular freedom 
for osmosis? What evidence has there been of a greater 
flow in one direction than in the other? What simple 
explanation for this may be offered ? As the liquid column 
mounts higher and higher, what sustains it in the tube? 
What measures the value of this osmotic pressure? 

2. Some substances in solution (like white of egg y and 
solutions of starch and of glue) osmose but little if at all. 
Such substances have been called colloids, distinguishing 
them from substances known as crystalloids whose solutions 
osmose readily. 

3. What condition of tissues is necessary that osmosis 
of gases may take place in the lungs whereby oxygen 
gets into the blood and carbon dioxide gets out? Dis- 
cuss in detail this process of interchange of gases in the 
lungs. 

4. What is the great purpose of the various steps in the 
digestion of food? What is the chief end to be attained in 
cooking food ? What makes up the large bulk of the diges- 

1 A rubber stopper previously slipped on over the upper end of the glass 
tube makes this suspension easily arranged. 



48 LABORATORY LESSONS IN GENERAL SCIENCE 

tive fluids? About what per cent of the blood is water? 
.What purposes are served by having this so ? 

5. Explain somewhat at length how the various cells 
of the body get their nourishment, and how they get rid 
of their waste products. When this waste matter gets 
into the blood, how is it disposed of ? Do the red corpuscles 
of the blood pass through the walls of the blood vessels? 
What is true of the white corpuscles ? 

6. What part does the solvent power of water play in 
the nourishment of plants? What part has osmosis? In 
the growing plant evaporation from the leaves (transpira- 
tion) rids the plant of relatively large volumes of its sap 
water. What part may this have in the rise of sap through 
growing plants? 

STUDY OF A STREAM 

1. Mention by name (or locate otherwise) the creek, 
brook, or river nearest to the school building. How far 
is it from the school (a) by highway; (b) by most direct 
route? Are there fish in its waters? If so, what kinds? 
If not, why not? 

2. What is true of the rate of its current at different 
places? In general is the current swift or sluggish? How 
could you determine quite accurately just how swift it is 
at any point? Why is it not swifter? Account for the 
direction of its flow. 

3. Describe the course of the stream so far as it is known 
to you, telling whence it comes, the general direction of 
its flow, and what becomes of its waters. Upon what does 



WATER, AND ITS USES 49 

the volume of its waters depend ? For how long a time will 
this stream naturally continue to flow? 

4. To what distances up and down have you followed the 
stream? Which is the right bank (a) of this stream; (6) 
of any stream ? Describe in a general way the character of 
country through which it flows, whether hilly, level, broken, 
or mountainous. Recall any relation between the char- 
acter of the banks of the stream and the rate of its 
current. What differences exist in the bed of the stream 
at different places? How are these accounted for? What 
explanation is there for any swift and broken current 
(" rapids")? What significance have places of compara- 
tively still water ? What is true of the widths of the stream 
at different points ? What relation has this to the depths 
at such places ? 

5. Of how much use in navigation is the stream? Why 
so? Has it any use for manufacturing? Why? Name 
other respects in which it is of use. 

VALLEY FORMATION, AND SURFACE EROSION 

1. From observations you have made of some gentle 
slope (by field, roadside, railway cut, or earth pile) where t 
the earth is bare and subject to wash by rains, state what 
relation is apparent between steepness of slope and (a) 
crookedness of the channels cut by the flowing surface 
waters ; (6) depths of the cuts ? Offer an explanation (a) of 
the crooks and turns in these channels ; (b) of the greater 
depths of some cuts than others. What is meant by erosion 
(e-ro'zhun) of soils? 



50 LABORATORY LESSONS IN GENERAL SCIENCE 

2. Distinguish between a main channel, and its trib- 
utaries. Why should there be any tributaries? What is 
meant by a divide between adjacent channels ? 

3. Make a sketch of some imaginary stream and its 
tributaries, and by appropriate lettering locate thereon 
(a) the main channel; (b) a tributary; (c) the mouth of 
the main stream ; (d) its source ; (e) a divide between two 




Fig. 20. — Canyon of the Colorado River. 

tributaries. Inclose by a continuous dotted line on the 
sketch what is included in the " water-shed" of the system. 
What is the meaning of (a) river basin; (6) river system? 



WATER, AND ITS USES 51 

4. How much is included within the limits of a valley f 
How many slopes has it? Explain the absence of streams 
in so many of the smaller valleys ? What various names are 
given to very small valleys ? Why have these valleys never 
become larger? Account for the existence of valleys in 
general. How may hills have been formed? Where hills 
of considerable height exist what is likely to be true of the 
nature of the material of which they are made ? 

5. Where flowing water makes cuts in the earth, (a) 
upon what factors does the rate of cutting depend; (b) 
which parts of the surface are most readily carried away? 
What significance is there in the muddiness of some surface 
waters ? Under what conditions will this muddy water be- 
come clear ? Why is it that streams made up of the surface 
waters from the hillsides in some parts of the country are 
clear, and quite free from sediment ? What is the relation 
of this to the fertility of those hillsides ? What becomes of 
much of the soil washed off into streams ? What is the in- 
evitable result of the continuance of this action upon (a) the 
fertility of farm lands ; (6) the surface level of the country ? 



VI. THE ATMOSPHERE 

SOME PROPERTIES AND USES OF AIR 

1. Empty a filled bottle of water. What goes into the 
bottle as the water flows out? 

2. Press a bottle mouth down into a jar of water, and 
over a floating bit of cork. Explain why water fails to 
enter and fill the bottle. 

Repeat, having an outlet through a rubber tube for the 
air that is in the bottle. 

3. By means of a piece of rubber tubing attached to a 
glass tube that passes through the stopper of a bottle, force 
into the bottle as much air as possible, and keep it there. 

What must be true of the condition of the air within the 
bottle now. Explain how it is possible to force more and 
more air into the bottle. 

Unclasp the delivery tube after putting its outer end under 
water, and observe what occurs. What must the air particles 
have done to one another? Explain how it is that water 
vapor finds place for itself in the atmosphere. What prop- 
erty of air is involved? 

4. Through a pipette * whose large end reaches down 
into water in a tightly stoppered bottle, force as much air 

1 Make by heating a piece of glass tubing till sufficiently softened to be 
easily drawn out into any desired size when removed from the gas flame. 
Allow it to cool, and break tubing as desired, making use of a sharp-edged 
file. 

52 



THE ATMOSPHERE 53 

as possible from the mouth into the bottle. Withdraw the 
mouth quickly to one side. Explain the fountain effect. 

5. Where about us is air to be found? Attempt to 
grasp a handful of it. Account for the inability to do this. 
Point to any air that you see. 

6. Look at a pencil through window glass. What 
property of the glass is manifest? Remove the glass, and 
look at the pencil through air. What property of air is 
manifest ? 

7. What odor has pure air? What taste? 

8. What is a chief constituent of air other than 
oxygen ? 

9. Name several uses served by air (a) when still; 
(6) when in motion as a wind. 

10. Write in a column a list of a dozen things you have 
known the wind to do. Then in a column, and opposite 
every such act, write adjectives characterizing it, using 
such words as saucy, tireless, gentle, angry, etc. Mention 
the various names given to winds by reason of variation in 
their force (intensity). 

11. What are the names given to winds according to 
the directions whence they blow? Name several ways 
in which wind directions may be somewhat accurately 
noted. 

12. Tell of the importance of winds to mankind in com- 
merce. In what ways do winds minister to man's comfort 
and to his discomfort ? In what ways do w T inds affect man's 
health? 



54 LABORATORY LESSONS IN GENERAL SCIENCE 

PRESSURE EXERTED BY THE ATMOSPHERE 

1. Tie in loose folds some thin sheet rubber over the 
large end of a thistle tube, making air-tight the rubber 
covering. Blow into the open end of the tube and observe 
the rubber. Compare the amount of air within the tube 
now and before. What must be true of the condition of 
the air within as compared with the air without the tube? 
Explain why the rubber is pressed outward. 

2. Using the same apparatus, suck some of the air from 
the tube and observe. Exhaust more of the air, and ob- 
serve again. Explain why the rubber is now forced inward, 
and why more in one c^se than in the other. What relation 
exists between the density of the air within the tube and its 
pressure upon the rubber? With the density of the out- 
side air remaining the same, how may the greatest inequality 
of pressure on the sides of the rubber be secured ? 

3. Closely fit into a wide-mouthed bottle a rubber stopper 
through which is passed two glass tubes, one of them long, 
and the other short and bent at right angles. Let the 
longer tube extend down into some water in the bottle. 
Through the short tube blow gently into the bottle and 
observe the water in the long tube. What change in con- 
dition of the air in the bottle results from blowing more and 
more air in ? Why does water rise in the long tube ? 

What relation exists between the degree of compression 
of the air in the bottle and the height of the water column ? 
What causes the rising column to come to rest ? How long 
will it remain stationary? 

Force water up into the long tube nearly to the top, and 
close the tube air-tight with one of the fingers, leaving a lit- 



THE ATMOSPHERE 



55 



tie air in the upper end of it. Remove the mouth from the 
short tube, and observe the water column. What is now 
true of the air pressures within and without the bottle? 
Exhaust some of the air from the bottle through the short 
tube, and observe the height of the water column. By 
what is the weight of the water in the long tube sustained? 

4. 1 Fill with mercury a glass tube that is at least thirty 
inches long and closed at one end. Holding the forefinger 
over the open end, invert the tube 
and put this open end down under 
mercury in a dish (a small mortar). 
Cautiously remove the finger, and ob- 
serve the upper end of the mercury 
column. Explain why the mercury 
column stands in the tube above the 
mercury level in the dish. Tip the 
tube back and forth sidewise for short 
distances, being careful to keep the 
lower end at all times below the sur- 
face of the mercury in the dish. What 
seems to be true of the space above 
the mercury in the tube? 

Measure the distance vertically up- 
ward, both in inches and in centimeters, from the surface 
level of the mercury in the dish to the level in the tube. 
How long will this height remain unchanged? What is 
true of this difference in levels as the tube is again tipped 
sidewise? As mercury is 13.6 times heavier than water, 

1 The part of this experiment making use of mercury should be done by 
the teacher. 




Fig. 21. — A simple 
barometer. 



56 LABORATORY LESSONS IN GENERAL SCIENCE 

calculate what height of water column would be supported 
by the same atmospheric pressure. 

5. If possible make a study of a mercury barometer, not- 
ing in it (a) the mercury cistern and how the air pressure 
from without reaches the mercury surface; (6) the heights 
of the mercury column from time to time, and from what 
point this measurement is taken in all cases ; (c) the provision 
for reading the height of the mercury column to the fraction 
of an inch. 

What would be the effect of the presence of any air within 
the tube (a) upon a rising barometer column; (6) upon a 
falling column? 

APPLICATIONS OF ATMOSPHERIC PRESSURE 

1. Tightly close the mouth of a tall bottle with a rubber 
stopper through which passes a pipette w T hose small end is 
inside the bottle. Attach a short piece of rubber tubing to 
the large end outside the bottle, and with the mouth by 
repeated efforts exhaust the air from the bottle, pinching 
the tube together while taking breath. Put the end of the 
rubber tube under water, and holding the bottle bottom 
up release the pressure on the rubber tube. Explain the 
action noted. What causes it to stop? 

2. Hold by the bottom a tumbler brimful of water. Press 
down closely upon the top of it a piece of cardboard, and 
then carefully invert the tumbler. Remove the hand from 
the cardboard, and explain why the water does not fall out. 

3. Insert one end of a glass tube into water and suck air 
from the other end. Explain why the water rises in the tube. 
What is a familiar application of this principle? 



THE ATMOSPHERE 



57 



Fill a bottle full of water, and with a rubber stopper 
carrying a long glass tube close the bottle air-tight, with 
water in the tube above the stopper. Attempt to suck water 
out of the bottle through the tube, and explain the results. 
Repeat the experiment, but with the bottle only partly 
filled with water, i.e., with some air in the bottle. Why are 
the results so different? 

4. Follow very closely the teacher's explanation of the 
action of both lift pumps and force pumps as these are 
illustrated by use of glass models, or by drawings at the 
blackboard. Then by the use of draw- 
ings on your papers write brief descrip- 
tions of both kinds of pumps. 

From explanations of the action 



5. 



of air pumps by the teacher, based on 
the operation of an air pump or on 
drawings at the board, write a descrip- 
tion of your own of their construction 
and operation. (Use any drawings that 
may aid in making your description 
brief and clear.) 

6. Fill with water a glass tube bent 
for use as a siphon (si'fon), one arm of 
which is only a little longer than the 
other. Holding a finger over one end 
so that the water will not run out of 
the tube, put the short arm of the 
siphon down into a tumbler filled with 
water, and then remove the finger. Infer (a) what causes 




J 



gz> ! 



£x 



Fig. 22. — The siphon. 
The lengths of the 
arms of the siphon 
are from the surfaces 
of the liquids at A 
and at D to the high- 
est part of the siphon 
at B. 



the water to rise in the tube above the tumbler top; 



58 LABORATORY LESSONS IN GENERAL SCIENCE 

(b) why the downward pull of gravity on the water in the 
long arm is greater than in the short arm ; (c) why water 
in the tube flows out of the long arm. 

Repeat the experiment, but have the outer arm of the 
siphon dip into water that fills another tumbler. Raise 
and lower first one of the tumblers and then the other, 
causing the water to flow back and forth. 

Where should measurements be taken to determine the 
length (a) of the short arm of the siphon; (b) of the long 
arm? 

7. From the lesson on Respiration recall and restate 
how the capacity of the chest cavity is increased and how 
it is diminished in natural breathing. Explain why air 
goes into the lungs, and why it goes out, making use of such 
drawings of the chest cavity as may be helpful. 

CAUSES OF CHANGE IN ATMOSPHERIC PRESSURE 

1. Close a test tube with a rubber stopper, through which 
passes a glass tube. Invert the tube and hold the end of 
the glass tube under water. Heat the test tube, and ob- 
serve what occurs at the mouth of the glass tube. Explain 
the behavior of the air of the tube. What is true of the 
density of the remaining air? 

Allow the tube to cool with the glass tube still under 
water, and account for what occurs. What is true of the 
density of air as it cools ? 

2. The weight of a cubic foot of air and of the vapor it 
contains in grains, with the barometer at 29 inches, and 
with the temperature in Fahrenheit degrees, is approximately 
as follows : — 



THE ATMOSPHERE 



59 



Degrees F. 


When Dry 


When Saturated 

with Water 

Vapor 


Weight of Water 

Vapor in 1 Cu. Ft. 

of Saturated Air 




32 

62 

102 


604.8 
564.9 
532.7 
494.9 


604.1 
561.4 
528.9 
461.3 


0.553 

2.128 

6.167 

20.979 



In the table, what is the relative density (a) of dry air 
and of saturated air at the same temperatures; (b) of air 
whether dry or saturated as the temperature is increased? 
What is true of the amounts of water vapor held by the air 
as its temperature is lowered? 

3. What must be true of barometer readings (a) in a 
warm moisture-laden atmosphere; (6) in a cold dry at- 
mosphere ? With a temperature stationary or rising, what 
is the probable cause of a falling barometer? What is the 
reasoning that forecasts rainfall when there is any consid- 
erable fall in the mercury column of the barometer? 

CURRENTS IN THE ATMOSPHERE 

1. In the first paragraph under 
Ventilation, what was true of 
the relative temperatures of the 
air in the two chimneys ? What 
will the air in the box do because 
of these conditions? Explain 
why the air goes down one 
chimney and then on through 
the box. What is true of the 
temperature of the warmed air 

», . . , . , . _ Fig. 23. — Convection currents 

alter it leaves the chimney ? in air. 




60 LABORATORY LESSONS IN GENERAL SCIENCE 

Trace its possible course to make a complete round of 
circulation. 

2. Trace the complete circulation made possible when 
in one region of the country there is a warm moist atmos- 
phere, and in some adjoining section the air is cold and dry. 
How long will this movement of atmosphere be maintained ? 
In what part of this circuit will the air current be along the 
earth's surface? Where will this air current cease to exist? 
Upon what will the velocity of the current largely depend? 

3. It may be well to distinguish between different parts 
of this circulation of atmosphere by limiting the use of the 
term wind to the current along the earth's surface as 
distinguished from ascending, descending, and upper air 
currents. Using the term in this way, infer (a) where a 
"wind" originates (springs up); (b) where it ends (ceases 
to be a wind) ; (c) from what direction it will blow. 

4. Where air currents are established, and regardless 
of changes of temperature and of moisture, what will be 
the effect on barometer readings (a) of the upward move- 
ment of the atmosphere ; (6) of the downward movement ? 

AREAS OF HIGH AND LOW PRESSURE 

1. In some parts of the world the sun at noon is directly 
overhead — is in the zenith. At what time of year is there 
nearest approach to that condition here ? What relation is 
there between the temperature of a region and the obliquity 
(ob-lik'wi-ti) of the sun's rays as measured by the angle 
between them and vertical rays ? 

2. That portion of the earth where the sun's rays are 
always vertical, reaches east and west around the globe 



THE ATMOSPHERE 61 

across northern South America, central Africa, and south- 
ern Asia. 

What must be one direct result of a continuous intense 
heating of the surfaces of the immense water areas of this 
region — the Torrid Zone? Name three causes that com- 
bine to make the barometer readings relatively low along 
the line where the sun's rays are all the time vertical — the 
so-called heat equator. 

3. As the hot moisture-laden air of the region of the heat 
equator ascends, in what directions other than upward is 
it likely to move in the upper air ? What change will occur 
in its temperature as it rises? What then becomes true 
of the amount of moisture this air can hold? What is 
true of its density as a result of these changes? As this 
upper air moves from the equator poleward, what becomes 
true of its elevation above the earth's surface ? 

4. In moving northward from the equatorial region over 
land areas of varying altitude, as on the continent of North 
America, in what portion of the continent are these upper air 
currents likely first to touch ground so that moving along 
the surface they again become winds? What is likely to 
be true of the character of any such winds fed by the descent 
of upper air as regards (a) temperature; (b) moisture? 
What other direction than northward will be taken by 
this atmospheric condition resulting from the downpour of 
upper air ? Why so ? What is likely to be true of the 
barometer readings of the sections of country over which these 
conditions shall in turn prevail ? 

5. With descending air currents in any one section of the 
country, what may reasonably be expected in some adjoining 



62 LABORATORY LESSONS IN GENERAL SCIENCE 

section if an equilibrium of the atmosphere is to be main- 
tained? What conditions of atmosphere in any region are 
likely to favor the development there of an ascending cur- 
rent? From how many directions will w r inds blow toward 
these areas of low pressure? At the center of one of these 
areas, why is there a "calm," — an absence of all winds? 
6. Describe the conditions of atmospheric circulation 
exhibited in these diagrams : — 

BROKEN CLOUDS CIRRUS CLOUDS 






•—- CLEAR 



*•:•:& 



HEAVY STRATUS CLOUDS »> > EAST 

DIRECTION 
OF MOVEMENT 

Fig. 24. — The theoretical movement of air in a " low." 



. •:•;•.-. CIRRUS CLOUDS 

CLEAR WEATHER 



BARTLY CLOUDY 



J*J J I ^ l \ V^ £?^ D . •STRbN^ WINDS ^ 0*^ 



DIRECTION 
OF MOVEMENT 



Fig. 25. — The theoretical air movements of a "high." 



VII. WEATHER AND CLIMATE 

WEATHER IN THE AFFAIRS OF MEN 

1. When people talk about the weather what are some of 
the comments usually made in connection with (a) temper- 
ature; (6) atmospheric moisture and precipitation; (c) 
winds ; (d) state of the sky ; (e) relation of weather to crops, 
and trade ; (/) effect on the health and well-being of people 
by reason of weather conditions? 

2. What in a general way is the relation of temperature 
(a) to latitude ; (b) to altitude ; (c) to situations far inland 
as contrasted with nearness to oceans? 

3. Compare conditions in the very cold regions, the torrid, 
and the temperate, as regards (a) the productiveness of the 
soil; (b) the working efficiency of man and of domestic 
animals. 

4. State any relation apparent to you between the change- 
able weather conditions of the temperate regions of the 
earth and (a) the prosperity of their peoples ; (b) the variety 
in their occupations, skill, and productiveness; (c) their 
advancement in learning, and the stability of their gov- 
ernments. 

5. In what ways has the human race sought to protect 
itself against weather changes aside from the kinds of food 
eaten? In our modern civilization by what further means 
do we seek to protect ourselves (a) from extremes in tempera- 
ture; (b) from exposure incident to travel and out-of-door 
occupations ? 

63 



64 LABORATORY LESSONS IN GENERAL SCIENCE 

6. In what ways is the manner of life of a people affected 
(a) by the excessive year-round heat of the torrid regions 
of earth ; (b) by sudden and extreme weather changes ; (c) 
by long-continued wet or dry periods ? 

7. Of what value to people are iveaiher forecasts that are 
reasonably accurate? Upon what must such predictions 
be based to have any especial worth ? For about how long 
in advance can reliable forecasts be made ? 

8. How much is known of the causes of deficient rainfall 
in any region some years, and of excess in other years? 
What control over these conditions has man? Explain 
what the mountain ranges of western United States have to 
do with any semi-arid conditions to the eastward of them. 




Fig. 26. — An irrigation reservoir. 



WEATHER AND CLIMATE 65 

9. Entirely apart from an ample water supply what 
must be true of land surfaces to make irrigation for large 
areas possible? Why is there need of national and state 
aid in developing irrigated districts? What industries 
are made possible in such districts? What are the ad- 
vantages and what the disadvantages of living on irrigated 
lands ? 

10. Describe any extensive irrigating system of which 
you have personal knowledge, or of which you have acquired 
definite knowledge by reading. 



WEATHER AS AFFECTED BY HIGHS AND LOWS 

1. From the weather maps of Figures 27, 28, 29, 1 showing 
the progress of typical storm areas, locate -and explain the 
significance of (a) the isotherms; (b) the isobars; (c) the 
wind directions from a high; (d) the wind directions into 
a low ; (e) the modification of temperature of a whole region 
by an advancing high; (/) the isotherms "running" with 
the lows; (g) the areas of precipitation. Explain any pre- 
cipitation in front of an advancing high. 

2. Account for wind directions at any point not in accord 
with the general atmospheric circulation about and into a 
low, or out from a high. What is the significance (a) of 
the term cyclone when applied to a low ; (b) of anti-cyclone 
applied to a high? What conditions largely determine the 
wind velocities reported at various points? 

] Get from the nearest Weather Bureau Station, if possible, some daily 
Weather Maps of recent date. Ask that those furnished be for successive 
days during a week or more. 
F 




66 




67 




00 

o 

05 



03 

P 

»-5 



o 

£ 







68 



WEATHER AND CLIMATE 



69 



ii 



100-- 



-212 



THE THERMOMETER 

1. Close a test tube filled with cold water with a rubber 
stopper through which passes a glass tube, and have the 
water stand above the stopper. Mark the water level in 
the glass tube by tying a thread around the tube. 

Warm the water in the test tube, and observe the effect 
as shown in the glass tube. Warm more 
and more, and observe further. 

Cool the test tube more and more, and 
explain any changes. 

State the general relationship apparent 
between change in temperature and change 
in volume. What is meant by the tem- 
perature of a body? 

2. Put a chemical thermometer having 
both centigrade (C.) and Fahrenheit (F.) 
scales into water, and take the readings of 
the mercury level when stationary in both 
C. and F. degrees. (Estimate any fraction 
of a degree in either case as tenths rather 
than halves, and quarters, and use decimals 
rather than common fractions in writing 
results.) 

Note how many spaces of the Fahren- 
heit scale the 0° F. is below 0° C. (the place 
where the mercury level stands when the 
thermometer is in freezing water). The 
temperature of the water is how many F. 
degrees above the zero of the C. reading? 
number of F. degrees (spaces) to which one C. degree of 
the thermometer stem is equal. (Carry the division out 



-17 



Fig. 30. — Fahren- 
heit and centi- 
grade scales in 
thermometers. 



Calculate the 



70 LABORATORY LESSONS IN GENERAL SCIENCE 

two decimal places.) Note how this compares with the 
value *'(1.8). 

3. Note on each scale how many degree-spaces there are 
between the levels of the mercury when in freezing water, 
and when in boiling water. Whence comes the f used above ? 
State how to change readings of centigrade scale into Fahren- 
heit readings, explaining why 32° is added to the reduction 
value found. 

4. State how the Fahrenheit readings may be changed 
into centigrade, and why 32° must now be subtracted 
before the reduction. 



TEMPERATURE RECORDS 1 

1. Take the temperature readings called for in the blank 
forms below, and record the same at the time taken. Let 
these observations be made daily during one week only in 
each succeeding calendar month throughout the school year. 





9:00 


12:00 


1:00 


4:00 


Monday . 


o 


o 


o 


o 


Tuesday 


o 


o 


o 
o 


o 


Wednesday 


o 


o 


o 


Thursday 


o 


o 


o 


o 


Friday 


o 


o 


o 


o 












Average 


o 


o 


o 


o 













1 Lessons requiring the keeping of records where data are to be gained by 
observation through considerable periods of time must be assigned suffi- 
ciently long in advance. It is unlikely that too great emphasis will be 
placed upon the educational value of sustained efforts to accumulate and 
classify facts. Such facts demand in themselves correct interpretation, 
and call for keenness of discrimination in relative values. There is cultivated 
that desirable mental attitude which seeks the truth at every step, and de- 
mands the facts before passing judgment. However important the facts 
of such lessons, their manner of acquisition and of use may be of even 
greater worth educationally. 



WEATHER AND CLIMATE 



71 



2. Note if the daily temperature changes appear to be 
repeated over and over. Explain the cause of such changes. 
Why are the midday temperatures highest ? 



. 








- . ......... ..... ., 


*%A 










• m 


% 


-■' ■ - 






:M 


4 




i2fi 




i 






9 

i 















-Fig. 31. — Temperature records. 

3. Transfer the averages found above to another tab- 
ulated form, thus : — 





9:00 


12:00 


1:00 


4:00 


September 










October 










November , 










December 










January 










etc ... 











72 LABORATORY LESSONS IN GENERAL SCIENCE 

4. At the end of each semester, and at the end of the 
school year, note the seasonal changes as shown in the 
twelve o'clock averages. Seek to account for them. 



SOLAR HEATING 

1. Set the insolation apparatus * in a south window and 
so adjust it that a beam of sunlight, passing through the 
box and falling upon a sheet of paper lying horizontal, 
shows the narrowest outlines of the box walls. 

2. Measure the area of the paper covered by the sun- 
beam that gets through the box, and tabulate the results 2 
called for in the form below : — 



Day 



Monday. . . 
Tuesday. . . 
Wednesday 
Thursday. . 
Friday .... 



Date 



9:00 
(a.m.) 



.sq. in. 
.sq. in. 
.sq. in. 
.sq. in. 
.sq. in. 



12:00 

(Xoon) 



. sq. in. 
. sq. in. 
. sq. in. 
. sq. in. 
. sq. in. 



4:00 

(P.M.) 



Obliquity s 

at 12 : 00 

Noon 



.sq. in. 
.sq. in. 
.sq. in. 
.sq. in. 
.sq. in. 



• deg. 

• deg. 
deg. 

• deg. 

• deg. 



Time of 

Highest 

Temperature 

'of Day 



Average 



1 A "breakfast food" carton with both ends removed serves the purpose 
well. To a block of wood sufficiently large and heavy to serve as a base, 
tack a strip of wood for an upright ; to this attach the carton in such a 
manner that it turns readily in a vertical plane. Turn the whole apparatus 
sidewise, and the carton up and down, to get the narrowest possible shadow 
of the walls of the carton. 

2 See footnote of lesson on Temperature Records. 

3 With a protractor measure the angle between the edge of the upright 
when vertical and the upper edge of the box as it stands properly ad- 
justed. 



WEATHER AND CLIMATE 



73 



3. Repeat these observations for one week at a time, and 
at about the same dates every calendar month throughout 
a school year. Transfer the "averages" for each week of 
observation to a second table as below. Only the data by 
months need be preserved in the notebooks. 



Month 


9:00 


12:00 


4:00 


Obliquity 


Hottest at 


September. . . . 
October 


. . .sq. in. 
. . .sq. in. 
. . .sq. in. 


. . . sq. in. 
. . .sq. in. 
. . .sq. in. 


. . .sq. in. 
. . .sq. in. 
. . .sq. in. 


deg. 

deg. 

deg. 






November. . . . 





(etc., for the whole school year.) 



4. With practically the same amount of heat (and light) 
getting through the box at different hours, what is the 



SUN'S PAYS 

REACHING EARTH SUN'S RAYS REACHING EARTH \r. 

AT NOON FROM AFTEROON WHEN SUN IS LOW IN 
NEARLY ABOVE HEAVENS. 




SURFACE OF THE EARTH G 



Fig. 32. — Difference in heat intensity of sunlight at different degrees of 

obliquity. 

relation between the area covered by the beam of sunlight 
and the heating effect of that same beam ? 

5. State what is noted in the monthly averages concern- 
ing changes in heat intensity (a) through the day ; (b) from 
month to month by seasons. 

6. State the relation apparent between obliquity of rays 
and seasonal changes. Account for this. 



74 LABORATORY LESSONS IN GENERAL SCIENCE 



7. Attempt an explana- 
tion of the fact that the 
highest temperature of the 
day comes later than noon, 
which is the time of great- 
est solar heating. 1 

8. Why is it warmer at 
sunset than at sunrise ? 









A. 


M. 










P.M.- 








M 2 46 810122 4 6 8 10M 1 




























26 : 
25 c 
24 : 
23 : 
22 : 

s 20 : 
19 : 
18 : 
17 = 





































































































































































































































































Fig. 33. — Range in temperature dur- 
ing twenty-four hours. 



9. Why is it that in 
northern latitudes the 
coldest weather is likely 
to be in January and 
February rather than in 
December ? 




Fig. 34. — Range of temperature during a 
year for five places having very differ- 
ent climatic conditions. The influence of 
the oceanic waters of the Tropics is seen 
in 4 and 5. 



1 It may be possible to make more clear the cumulative heating by day, 
and throughout a summer, by use of several dishes of different capacity 
and a vessel of water. The gain and the loss of heat per hour at the place 
where the observer is stationed on the earth may be represented by quanti- 
ties of water added to or taken from an original volume in the vessel. The 
hourly losses by radiation from the earth through a 24-hour period may be 
considered as approximately the same for any observer. The gain in heat 
per hour increases up to noon, and then decreases, although for some time 
after the noon hour the gain per hour exceeds the loss. 



WEATHER AND CLIMATE 



75 



GENERAL WEATHER RECORD i 

1. As assigned by the teacher, collect and tabulate the 
data called for below : — 



Date 


Tempera- 
ture 


Pressure 
(Note 1) 


Wind 
Direction 
(Note 2) 


Amount of 

Precipitation 

(Note 3) 


State of 
Sky 2 




o 


in. 




in. 






o 


in. 




in. 


* 




o 


in. 




in. 






o 


in. 




in. 






o 


in. 




in. 
















Average 


o 


in. 


(Prevailing 
wind) 


(Total) 


(Number of 
clear days) 



2. From the data gathered above, and from the tabulated 
averages and totals, seek to discover : — 

(a) The prevailing wind characteristic of any season. 

(b) The relative amount of precipitation by months and 
by seasons. 

(c) Any seasonal round of clear and stormy weather. 

(d) The temperature ranges and averages for the differ- 
ent seasons. 



1 See footnote of lesson on Temperature Records. 

2 By use of a circle (O), a clear, partly cloudy, or overcast sky may be 
shown by the degree of shading ; an inclosed R = rain, and an S = snow. 

Note 1. Some one in the community may have a barometer from which 
readings can be taken in case the school does not possess its own instrument. 
If necessary, omit the pressure readings, as well as (/) and (h). 

Note 2. A sufficiently good weather vane may be made and mounted on 
the schoolhouse by any local mechanic, or by one of the older pupils. 

Note 3. Where a rain-gauge (gaj) is not available, a tin can with straight 
sides (such as a large-size baking-powder can) may be set into a light frame- 
work to keep it from being blown away. Put the can out in the open away 
from trees and buildings. Using a foot rule graduated to 16ths of an inch, 
measure the depth of water in the can, always holding the rule vertical. 



76 LABORATORY LESSONS IN GENERAL SCIENCE 

(e) Any apparent relation between wind direction, tem- 
perature, and rainfall. 

(/) The relation of barometric fluctuations to weather 
changes. 

(g) Any relation between wind direction and state of the 
sky. 

(h) Temperature and barometric changes during the pass- 
ing of a low. 

3. From the data accumulated at the various Weather 
Bureau Stations since the establishment of the U. S. Weather 
Service in 1870, state what appears to be true of: — 

(a) Any relation between the weather and " changes in 
the moon/' i.e., changes in its phases. 

(6) Accuracy in any detailed weather forecasts for a year 
ahead. 

(c) The recurrence of approximately the same changes of 
weather for recurring seasons. 



VIII. AT OUR HOMES 1 
ROOMS OF THE HOUSE, AND THEIR FURNISHINGS 

(a) The Kitchen 

1. What is the relative use of the kitchen and of the other 
rooms of the house during the day ? Why is it best not to 
have the kitchen a large room ? What is a good size for it ? 
Using a scale of -§- inch = one foot, represent on your paper 
a desirable size and form for a kitchen. 

2. Name some of the kinds of work carried on in a kitchen 
in connection with the weekly routine of household duties. 

3. State what economies are possible in the purchase and 
storage of coal for household use. Name various kinds of 
coal, and tell their relative fuel values. What special care 
should be given the kitchen coal stove (or range) ? What 
may be done to keep fire overnight in it ? Tell how to build 
a fire in the stove (or range), and how to avoid waste of coal 
in the ashes. 

4. About what is the cost of a gas (or gasoline) range? 
What is the cost of gas (or of gasoline) ? In what ways may 
there be waste in the use of gas in the kitchen ? Explain the 

1 While much that is required in these lessons on the home may be matter 
of common knowledge to the pupils generally, it is nevertheless urged that 
there be considerable discussion in detail of household economies and 
household management. However, any mere statement of the facts re- 
quired by these lessons is far less important than the establishment of whole- 
some ideals of a simple manner of living, and a realization of the possibil- 
ities of a modern American home. 

77 



78 LABORATORY LESSONS IN GENERAL SCIENCE 

economy of a fireless cooker where gas is used for fuel. 
Name several advantages in the use for fuel (a) of coal; 
(b) of gas. 

5. Of the kitchen sink tell (a) the kind and size desirable, 
and its cost; (6) the purpose of a trap for it; (c) how to 
keep the waste pipe from becoming clogged, and how to clean 




Fig. 35. — Kitchen furnishings. 

it from time to time. What is the cost of water in your town 
for household uses ? What are some advantages in the use 
of cistern water? Name some conveniences to be kept at 
or near the sink. Why is it better to have open plumbing 
(pipes exposed) than to have the pipes inside partitions or 
cupboards ? 



AT OUR HOMES 



79 



6. About what is the cost of a kitchen table (or kitchen 
cabinet) ? What conveniences should the table (or cabinet) 
provide ? What kind of a top should the kitchen table have ? 

7. What need is there of doors for kitchen cupboards? 
Give a list of the dishes and utensils likely to be kept in a 
kitchen cupboard. 

8. What are the objections to a soft wood floor for the 
kitchen ? Why not have painted floors ? What care should 
be given oiled hard- 
wood floors ? State 
objections to having 
any floor covering. 
What is the cost of 
linoleum? What 
should be done from 
time to time to keep 
the linoleum imper- 
vious to water ? 

9. What are va- 
rious finishes for 
kitchen walls? Dis- 
cuss their relative 
cost, and their other 
merits ? 

10. Why should 
there be screens at the kitchen windows? Why remove 
and store the screens during the winter ? 

11. What are the advantages in having a separate room 
for a kitchen pantry? Why have cupboards in it? Why 
have a window ? 




Fig. 36. — Food may be kept in a box just 
outside the pantry window. 



80 LABORATORY LESSONS IN GENERAL SCIENCE 

12. Name several considerations that influence the choice 
of a position for the refrigerator for household uses. State 
the special care that should be given it. 

13. Make a floor plan, drawn to a scale, showing the re- 
lation of the kitchen to (a) back yard and back porch; 
(6) basement; (c) dining room; (d) pantry. (Make the 
arrangement of rooms such that the paths most frequently 
traveled to and from the kitchen range shall be the shortest 
distances.) 

(b) The Dining Room 

1. What is a usual size and form for the dining room ? 
What furnishings are needed for it ? What is a satisfactory 
floor covering for the dining room ? 

2. Discuss (a) the dining room table — its material, cost, 
and the proper care of it ; (b) the kind and cost of dining 
room chairs; (c) the need of a sideboard, and its cost; 
(d) the advantages of a "built-in" china closet. 

3. When the breakfast table is "set" for five, (a) what 
are suitable dishes and tableware, and how are these to be 
arranged? Name some foods ("dishes") for a balanced 
"two-course dinner." 

4. What care should be given the dining room daily? 
What objections are there to eating in the kitchen? 

(c) Bathroom 

1. Where with reference to other rooms may the bathroom 
be (a) in a one-story house; (b) in a two-story house? 
What kind of wall is desirable? How may hot water be 
provided for the bathroom ? 




81 



82 LABORATORY LESSONS IN GENERAL SCIENCE 




Fig. 38. — Furnishings of a bathroom. 

(d) Sleeping Rooms 

1. Where usually are the sleeping rooms in a house ? Why 
may it be desirable to have a sleeping room downstairs? 
What is a good size for a sleeping room ? What furniture is 
desirable other than bed, couch, or cot ? Mention desirable 
conditions as to (a) windows ; (b) closets ; (c) floor covering. 



(e) Living Room 

1. What is the advantage of a hall or vestibule leading into 
the general living room ? Discuss the cost, construction, and 
size of a desirable kind of library table, and various provisions 
for artificial light to use with it. Describe some desirable 



AT OUR HOMES 



83 



kinds of bookcases, and make a list of some good books for 
the home bookcase. Make a list of other furnishings, such 
as chairs, rugs, etc., and give their probable cost. 



Co/d VV<9/^?- 



(f) Basement 

1. To what use is a basement commonly put? What is 
its value in the matters of health, and of warmth for the 
rooms above? How may it be made rat-proof? 

2. Name several kinds of heating plants. So far as pos- 
sible tell something // ^ 5/pr 
definite (a)' of their 
relative cost; (b) of 
their period of use- 
fulness; (c) of their 
expense of mainte- 
nance. Why is there 
need of a separate 
room for coal ? How 
may the dust be les- 
sened when coal is 
handled ? 

3. Why is it well 
to have the laundry in 
the basement ? Name 
desirable furnishings 
and conveniences for 
it. What other place may there be in the house for drying 
clothes indoors in stormy weather ? 

4. Copy the diagram given, and by use of arrows show 
how from a " water-front " in the kitchen range hot water may 




Fig. 39. — Hot water from the kitchen range. 



84 LABORATORY LESSONS IN GENERAL SCIENCE 

be provided for the kitchen sink, a bathroom upstairs, and 
a laundry in the basement. 

5. Make a diagram showing a hot tvater*plant in the base- 
ment, with radiators for one room each on the first and second 
floors, and an overflow tank. What special care is necessary 
in the location of pipes, and in plans for their drainage ? 

THE COST OF LIVING 

(a) Food 

1. About what is the cost of cereals (se're-als) per pack- 
age ? This is about how much per pound ? Tell the manner 
of cooking and serving them. What is the economy (a) of 
buying them in bulk ; (b) of cooking them with a fire in use for 
other purposes? What range of choice is there in " break- 
fast foods" ? Why is it wise to make use of different kinds 
of grains from time to time? How do the nutritive values 
of the cereals compare with one another and with meat ? 

2. About what is the cost of eggs in summer and in 
winter? How is the storage of eggs in quantity at home 
accomplished ? 

3. About what is the cost of coffee per pound ? What is 
the manner of its preparation for table use? About how 
many cups of drink are made from a pound of it? What 
limitations in its use as a drink should be observed by adults 
and by children ? 

4. What are desirable foods for breakfast? What is 
true of the nutritive value of fruits? What are reasons 
other than cost for not having meat and potatoes for 
breakfast ? 



AT OUR HOMES 



85 



CARBOHYDRATES 



THE HEAVY BLACK LINES IN THE CHART BE- 
LOW INDICATE THE RELATIVE FUEL VALUE 
IN ONE POUND OF EACH OF THE NUTRIENTS 




Fig. 40. — The relative values of foodstuffs. 



86 LABORATORY LESSONS IN GENERAL SCIENCE 

5. About what is the usual cost of potatoes, fall and 
spring? What are necessary conditions for their storage in 
quantity in the home? Name ways of preparing them for 
table use (a) for the sake of variety; (6) for purposes of 
economy ; (c) with reference to the season. 

6. What are the prevailing prices of different cuts of 
beefsteak ? What are their relative nutritive values ? How 
should steak be cooked, and why so ? What is the relative 
cost of steak, and of meat for boiling ? What is their relative 
value as foods? What cooking procedure in the boiling of 
meat gives best results ? What management will save fuel ? 
What is the manner of preparation of soup, and what is its 
food value ? 

7. About what is the cost of butter per pound, and of 
bread per loaf? What economies are possible in the use of 
butter? Discuss substitutes for butter in cooking — their 
food value, and their wholesomeness. 

8. Give the cost of various kinds of garden stuff in sea- 
son, — as corn, peas, string beans, asparagus, rhubarb, 
beets, tomatoes, radish, lettuce, cabbage. What table 
variety may be had in canned vegetables? What is their 
usual cost per can ? What is the relative nutritive value of 
canned and fresh vegetables? Discuss the relative cost of 
home canned goods and the factory product. 

9. Name various forms of dessert in common use, and 
give their relative cost. 

10. Mention the various dishes in common use for sup- 
per, their relative cost, and their wholesomeness. 



AT OUR HOMES 87 

(b) Clothing 

1. Name the two chief economic ends in view in the pur- 
chase of clothing. By what is one to be guided in judgment 
as to (a) real values in clothing ; (6) wearing quality ? What 
general rule is to be followed in making purchases because 
articles are "cheap"? What advantage is there in buying 
from reputable firms with well-established business standing ? 

2. What is true of the cost of the same articles (as of suits 
and millinery) "in season" and "out of season"? What 
differences in the cost of clothing for the year may result 

(a) from purchases at favorable times ; (b) from wise selec- 
tions as to service ? 

3. Discuss the extent of economies possible through the 
making of garments at home. What is the value in the home 
of a knowledge (a) of dressmaking ; (b) of millinery ? How, 
where, and when is this knowledge to be gained ? 

4. Discuss extravagances (a) from extremes in fashion; 

(b) from choice of what is not suited to intended uses; 

(c) from lack of care in wearing, or in storage. 

5. Make lists (several items each) of articles that belong 
in the class (a) of things which must be provided for com- 
fort and well-being; (b) of luxuries, whether wholesome in 
influence or not. 

6. What constitutes a good standard in dress for anyone 
to follow? To what extent shall fashion (the prevailing 
mode) be followed by anyone ? 

(c) Rents 

1. Name many advantages from ownership of one's home. 

2. What items are to be calculated in the cost of owning 



88 LABORATORY LESSONS IN GENERAL SCIENCE 

one's home in addition to (a) interest on sum invested; 
(b) insurance ; (c) repairs (on an average) every year ; 
(d) taxes ; (e) depreciation in property through use ? 

3. Name the several factors entering into a calculation of 
rental values. 

(d) Other Items in the Cost of Living 
1. Name various furnishings of homes not before men- 
tioned. 




SUNDRIES 
$90.00. 



Fig. 41. — A division of the family income. Note the items, and their rela- 
tive values. What are the savings from an income of $1000 ? 



AT OUR HOMES 



89 



2. Aside from bills for physician, nurse, and medicines, 
what are the economic reasons for keeping in good health ? 

3. What are arguments to warrant expenditures for schools 
and churches in a community ? 

4. What is the cost (a) of a telephone; (6) of electric 
lights ; (c) of city water ; (d) of a daily newspaper ? 

5. Why is it necessary to levy and collect taxes? For 
what are such moneys to be spent? Upon what basis is 
anyone's share of taxes to be determined? 

6. What argument is there for including some outlay for 
amusements in the cost of living ? What is a safe standard 





Fig. 42. — Wholesome exercise, and great sport. 



whereby to judge if any form of so-called amusement is 
wholesome and fit to indulge in? What (relatively) need 
be the amount set aside to spend for amusements ? Why so ? 



90 LABORATORY LESSONS IN GENERAL SCIENCE 

FIRES, AND BURNS 

1. Recall from the lesson on Combustion the relative 
ease with which kerosene and gasoline ignited, and restate 
the reason for it. 

2. What is meant by (a) explosive vapors; (b) inflam- 
mable gases? Under what conditions will explosions of 
gases occur? Explain the destructiveness of an explosion 
of gas. Why oftentimes is there an instant spread of fire 
accompanying the explosion? Why not use water to ex- 
tinguish burning oil ? What material likely to be at hand in 
the kitchen may be used ? 

3. What, as a physician sees it, is the nature of burns? 
What is the usual treatment for them? What is a blister? 
How proceed to drain out the fluid of a blister ? 

4. Why are results so likely to be fatal when a large 
area of the body surface is seriously burned ? What treat- 
ment will allay the torment from the irritated nerve ends of 
the burned area ? 

5. What is meant by internal burns, and why are they 
likely to prove fatal? What is meant by being suffocated 
by smoke? What is a wise precaution when compelled to 
grope one's way through smoke ? 

6. Explain the explosion when kerosene is poured upon 
hot coals in a stove. What precautions should be taken when 
using gasoline at home to clean clothing? In case one's 
clothing catches fire at any time, why is it usually better 
(a) not to run ; (b) not to stand erect ? 

7. When may illuminating gas at the kitchen range 
become a source of danger ? What danger is ever present in 



AT OUR HOMES 



91 



the use of gas lights ? Wherein is there possible danger from 
putting fresh coal into the stove or the furnace just before 
going to bed ? What is a wise precaution to take ? 

8. What material is used in making the heads of friction 
matches? Explain why they ignite from friction. When 
may their ignition be spontaneous ? For what reason other 
than danger in their use is the manufacture and sale of 
matches containing yellow phosphorus objectionable ? What 
is the nature of safety matches ? 

9. What is meant by "defective wiring" which is said 
to be the cause of so many losses by fire? Why are cigar 
stubs thrown aside pecul- 
iarly dangerous as sources 
of fire? 

10. Discuss the nature 
of some one of the many 
kinds of fire extinguishers on 
the market. Under what 
circumstances may these 
be of large service ? Before 
going to bed in a strange 
hotel, what is a wise course 
to take for safety in case 
there should be a fire during 
the night ? 





fia 2 C03 SOLUTION 



I 



Fig. 43. — A portable fire extinguisher. 



11. About how much is 
the insurance charge for 
three years on a dwelling and household goods to the 
amount say of three thousand dollars ? Why is the cost so 



92 LABORATORY LESSONS IN GENERAL SCIENCE 

great ? To about what per cent only of the real valuation 
should property be insured ? 

12. From the bulletins of the State Fire Warden and the 
regulations of local fire officials concerning prevention of 
fires, gather and be able to restate understanding^ some of 
the warnings and requirements as to (a) the accumulation 
of rubbish, and the starting of fires in dry weather ; (6) the 
care of matches and of inflammable liquids. 

ACCIDENTS OTHER THAN BURNS 

1. What is the danger from any slight wound where the 
skin is cut or torn ? What is the chief value of the " first aid " 
bandages and treatments on the battlefield? Explain the 
festering of slivers under the skin. 

2. What is believed to be one of the offices of the white 
corpuscles in the healing of wounds ? What is generally true 
of the chance for recovery from wounds, or from surgical 
operations, of persons who are users of alcoholic drinks? 
Why is this ? 

3. Where poison has been swallowed, what can be given 
(a) as an emetic that the stomach be freed of the poison 
before it can be absorbed ; (b) to hinder absorption, and 
lessen any harmful action on the stomach walls? What 
should be an enforced rule of every household as to (a) place 
for keeping poisons of any sort in the home ; (b) labels on 
bottles and packages of poisonous substances ? 

4. Mention some of the ways in which street railway 
managers ask the cooperation of parents and of the traveling 
public in avoiding accidents. Why must efforts in this 
respect be made year after year ? 



AT OUR HOMES 93 

In which direction should one face in alighting from a 
street car? Why is there less likelihood of being thrown 
when this rule is observed? Which hand should be free to 
grasp the railing (a) when mounting a car; (6) when dis- 
mounting ? 

5. What in general is meant by the "safety first" crusade 
in the industries and in transportation? When are em- 
ployers of labor justly held liable for accidents to employees ? 
Why is there need of State Inspectors for shops, mills, fac- 
tories, mines, and all places where labor is largely employed ? 
What are the provisions in your community (if any) for fire 
escapes on buildings ? 

6. Why should we condemn a person who recklessly im- 
perils the lives of others as, for instance, one who rocks a 
boat or in a crowded house gives an alarm of fire "just for 
fun" ? What is meant by " criminal negligence" on the part 
of a person, business firm, or corporation ? 

7. What are the tests for fitness (a) of engineers of 
railway locomotives ; (b) of drivers of automobiles ? Who 
only are allowed to run stationary engines? What ends 
might be attained by a system of licensing automobile 
drivers ? 

8. Discuss the effect on the life and usefulness of a man 
from the loss of one leg by accident when a boy. 



IX. HOUSEHOLD CHEMISTRY 
A REVIEW OF SOME CHEMICAL CHANGES 

1. So common are chemical changes in everyday life, 
and so important are these to our well-being and comfort, 
that it will be profitable to recall some already studied in 
connection with others more or less familiar in home 
affairs. 

What in general is the nature of the chemical change 
that occurs in stoves and furnaces in warming our houses? 
What explanation is there for the heat produced in our 
bodies ? What are the products of the oxidation (a) of car- 
bon; (6) of hydrogen? 

2. How is it that low temperatures, lack of moisture, use 
of preservatives, and the common processes of canning, 
hinder or prevent the decay of organic foodstuffs? Name 
some preservatives of foods that are (a) wholesome; (6) 
prohibited because they may be harmful. 

3. What is the significance of the term fermentation f 
What is the general purpose of the changes in the processes 
of digestion? Into what stage of chemical change in foods 
does fermentation lead if unchecked? What in some cases 
is the nature of the ailment called indigestion? Why in 
the fermentation of cider to make vinegar, and in the sour- 
ing of milk, does the increase of acid cease after a time? 
Explain the destructive action on the teeth of decaying food 

94 



HOUSEHOLD CHEMISTRY 



95 



lodged between them? What is the nature of the yeast 
used in bread-making ? What is secured through its use ? 
What effect on the yeast has baking the bread ? 

4. Where soil is open and porous enough for free access 
of the oxygen of the air, and at the same time sufficiently 
moist, what chemical changes favorable to plant growth 
may occur (a) in the humus of the soil ; (b) through the 
agency of nitrogen-fixing bacteria ? 

5. What very largely is the "dust" that accumulates on 
the floors and furnishings of our homes? Aside from its 
irritating effects on the 
air-passages and in the 
lungs, what positive dan- 
ger is there in breathing 
it? Where besides in 
our homes is there dan- 
ger from breathing dust ? 
What is meant by infec- 
tion ? What diseases or- 
dinarily find their way 
into the body as germs in 
the air we breathe ? 

6. What precautions 
should be taken to avoid 
filling the air of rooms 
with dust when sweep- 
ing and when dusting ? ' 
What adds to the dust nuisance in schoolrooms ? What is 
a common ailment of workers in factories where the air is 
filled with dust from wood, metal, or cloth? 




Fig. 44. 



- Use a damp cloth, or oiled rag, 
when dusting. 



96 LABORATORY LESSONS IN GENERAL SCIENCE 

7. What is the active chemical agent in the hypochlorite 
of lime (and "bleaching powder") used to purify the water 
supply in city w r ater systems, the soiled clothing from per- 
sons sick with infectious diseases, and the air of cellars and 
basements not kept well ventilated? Name several other 
disinfectants whose value lies in their chemical action upon 
disease germs. 

THE CHEMISTRY OF CLEANING 

1. For scrubbing floors, washing windows and table dishes, 
and for toilet and laundry purposes, soap is employed to an 
extent that has led to the statement that the civilization of 
a nation may be judged by the amount of soap its people use. 

What in general is true of dissolving oils and fats in water, 
either cold or warm? What is the nature of butter? In 
what size of particles must its material be when scattered 
through milk ? Ascertain the meaning of the term emulsion, 
and show how it applies to milk. 

2. What is a common effect upon the skin of the use of 
laundry soap ? Test some strong soap solution with a strip 
of red litmus paper. If it is turned blue, the soap solution 
is said to have an alkaline reaction (or alkaline effect). De- 
termine by use of litmus paper whether laundry soap or 
toilet soap is more alkaline. What should be true of toilet 
soaps with regard to an excess of alkali? Ascertain the 
nature of (a) scouring soaps; (6) "sapolio." 

3. Why is "hard water" objectionable for toilet and 
laundry purposes ? Why is cistern w T ater more satisfactory ? 
Why is not cistern water available for household purposes 
everywhere? Where "soft water" is not available for 



HOUSEHOLD CHEMISTRY 97 

laundry use, what very commonly is done before making use 
of soap in washing clothes? Test with litmus paper a 
solution of any washing powder at hand to determine its 
nature. 

4. From reference books, or other sources, ascertain 
what to do in order to remove from cloth (a) spots of com- 
mon ink ; (6) coffee stains ; (c) paint spots ; (d) grass stains. 

5. How may varnished surfaces, whether polished or 
waxed, be cleaned without harm to them ? How is tarnish 
removed from metals, such as silverw T are? How do you 
account for the blackening of silverware (a) by eggs; (b) 
by contact with rubber ? 

6. Watch very closely the bleaching effect on small pieces 
of cheap calico, and upon stains on white goods, when these 
are dipped repeatedly into a solution of bleaching powder 
to which strong vinegar is added. Notice the odor of the 
bleaching powder. What is the chemical agent active in 
the bleaching? 

ACIDS, BASES, AND SALTS 

1. Making use of small strips of litmus paper test the 
effect on it of vinegar and of fruit juices (as lemon, orange, 
grapefruit, cherries, etc.) ; of ammonia water, limewater, 
and drinking water ; and of solutions of baking soda, washing 
soda, borax, soap, and common salt. Arrange these sub- 
stances in columns under the headings acid, alkaline, and 
neutral, according as the litmus paper is turned red, or blue, 
or is unaffected in color. 

To the list as above add a half dozen or more tests of 
other solutions. 



98 LABORATORY LESSONS IN GENERAL SCIENCE 

2. Follow very closely the results as the teacher carries 
out the following directions : — To a solution of baking 
soda in an evaporating dish add drop by drop some dilute 
hydrochloric acid (HC1) till, as the solution is stirred thor- 
oughly, it does not affect the color of litmus paper, i.e., 
till it is neutralized. If too much acid is added at any time, 
more of the soda solution may be added drop by drop. 
When the solution becomes neutral, evaporate it to dryness, 
heating till no more vapors pass off. Identify the solid 
that remains by tasting it. 

SOME CARBONATES 

1. In the lesson on Combustion what was discovered re- 
garding the effect of the expired breath upon limewater 
(Ca0 2 H 2 ) ? What was the explanation of the change in its 
appearance? The precipitate (the solid formed as result of 
chemical change) is calcium carbonate (CaC0 3 ). 

2. Force air out from the lungs through a glass tube that 
reaches down into 10 c.c. of limewater in a test tube, and 
continue until the limewater becomes clear as at first. The 
solid particles of the carbonate of "lime" apparently dis- 
solve. Test the liquid with litmus paper to determine its 
nature. 

To explain what has occurred, it may be supposed that car- 
bon dioxide combines with the water as shown in the equation 
C0 2 + H 2 —> H 2 C0 3 (carbonic acid), and this in turn with 
the limewater thus : — Ca0 2 H 2 + H 2 C0 3 -> H 2 + CaC0 3 . 
But when an excess of H 2 C0 3 has been formed by reason of 
continued breathing of C0 2 into the limewater, the further 
change whereby the limewater becomes clear again may be 



HOUSEHOLD CHEMISTRY 99 

represented in the equation CaC0 3 + H 2 C0 3 — ^H 2 Ca (003)2, 
in which the resulting new substance known as acid calcium 
carbonate is soluble in water. 

Whether these chemical changes occur as a series of steps 
in the order indicated, or are more or less coincident, is of 
far less importance than it is to have set forth in the equa- 
tions that which is known to be true concerning what sub- 
stances as factors enter into the chemical change, and what 
substances result as products. 

3. Learn definitions for acid, base, and salt as used in 
Chemistry. Show very definitely how the substances whose 
formulae are CaC0 3 , Ca0 2 H 2 , and H 2 C0 3 , respectively, meet 
these conditions. It will be noted that in the formula for 
the acid calcium carbonate there appears not only the 
metallic atom Ca from the base, and the radical C0 3 from the 
acid, but some H from the acid appears also in the formula 
of the salt. This formula H 2 Ca(C0 3 ) 2 is a good illustra- 
tion of the class of so-called acid salts. It must be remem- 
bered, however, that it is upon the presence of the hydrogen 
atoms in the molecule of the acid salt, and not upon the 
effect shown by litmus paper, that the classification of salts 
as normal and acid depends. In the case of the salt known 
as acid sodium carbonate (HNaC0 3 ) the solution as shown 
by use of litmus paper is strongly alkaline. 

4. Note the appearance and taste of both sodium car- 
bonate (Na 2 C0 3 ) and acid sodium carbonate. The latter is 
"baking soda/' and the former is known as "sal-soda," 
and as "washing soda." Test the gas given off as a little 
hydrochloric acid is added to portions of each of these 
salts in test tubes. (Hold down in the tube above the 



100 LABORATORY LESSONS IN GENERAL SCIENCE 

effervescing liquid a glass rod having a drop of clear lime- 
water on its lower end. This is the usual test for carbonates.) 
Repeat the test, using in turn a small lump of marble, and 
then one of limestone. Try bits of egg shell, and of any 
other shells at hand. Test any fragments of rock provided, 
and pieces of old mortar. Be sure to note about what por- 
tions (if any) of the marble and of the limestone fail to dis- 
solve in the acid. Account for any such failure. 






X. THE HOME SURROUNDINGS 



A GARDEN IN THE HOME LIFE OF A FAMILY 



1. Aside from the money value of its produce, what are 
excellent reasons for having a small but well-kept garden con- 
nected with every 
home ? Name some 
of the common 
amusements for a 
boy in town. 
Wherein is an ac- 
tive interest in the 
home garden, and 
the employment in 
it of one's spare 
moments, superior 
to any of them? 
What part may 
the mother and 
daughters of a 
family have in the 

Care of a garden ? Fig. 45. — Counting the profits from the garden. 

2. Explain how it is that in the care of the home garden 
a boy may learn (a) to know the conditions for plant growth ; 
(b) to understand economic values in home life ; (c) to as- 
sume responsibilities and to discharge duties. 

101 




102 LABORATORY LESSONS IN GENERAL SCIENCE 

3. Trace a relation (a) between lack of home occupations 
on the one hand, and vicious and evil ways on the other ; 
(6) between industry and capable management in the small 
affairs of life at home during childhood, and the likelihood 
of becoming worthy and successful men and women. 

4. In order to plan, plant, tend, and carry through to 
success a season's gardening, (a) what characteristics must be 
possessed (or developed) other than strength of muscle ; (6) 
what lessons not of books are likely to be learned? How 
may "initiative" (ui-ish'i-a-tiv) be developed in the care of 
a garden? 

5. Why is it better to have the care of a garden at home 
than to depend upon a school garden ? On the other hand, 
what excellent purposes are served by a school garden? 
What application here has the saying, " What is worth doing 
at all is worth doing well"? 

THE CARE OF A GARDEN 

1. In planting small seeds like beet, onion, lettuce, radish, 
turnip, carrot, parsnip, (a) about how far apart should the 
rows be placed; (b) about how far apart should the 
plants be allowed to grow; (c) about how close should 
the seeds be sown; (d) about how deep should the seeds 
be covered? How deep should the soil have been over- 
turned and made loose for these seeds? Why should the 
surface layer be raked much more than is necessary to 
make it smooth ? 

2. About how far apart should the rows be, and how far 
apart the plants in a row, for (a) corn, potatoes, beans; 
(6) cabbage, tomato, and sweet potato plants as trans- 



THE HOME SURROUNDINGS 



103 



planted? What is the advantage of transplanting over 
putting the seeds in place? What special preparation of 
the ground is made for sweet potato plants ? What is the 
manner of planting the common potato ? Why is there less 




Fig. 46. — At work in the garden. 

need of care in the preparation of the soil for corn and po- 
tatoes than for onions, radish, and lettuce ? 

3. Examine closely the various garden seeds provided in 
the small labeled vials so you may be sure of making no 
mistakes later when you will be required to recognize at sight 
and to name any kind given you from unlabeled lots. 

What is meant by a seed ? What are the conditions under 
which the life dormant within it becomes manifest? 



104 LABORATORY LESSONS IN GENERAL SCIENCE 



4. For what chief reason other than keeping down weeds 
ought there to be frequent stirring of the surface layer of 
soil throughout the growing season ? Aside from the untidy 
appearance they give, what harm is there in allowing weeds 
to grow ? What course, if followed consistently, will destroy 
the weeds of a garden during the growing season with the 
least outlay of time and strength? Under what condition 
of the soil is it more harmful than beneficial (ben-e-fish'al) 

to work it ? Why is it well 
to plow (or spade) some 
gardens late in the fall ? 

5. About how long after 
planting may one expect 
ready for use (a) radish; 
(b) green peas; (c) string 
beans ? How may a supply 
of radish and of beans be 
secured at intervals (or in 
succession) ? What differ- 
ent course may be followed 
with peas and with corn? 

6. On one side of your 
sheet of paper represent a 
garden plot 30 feet X 40 
feet, using the scale \ inch 

= one foot. Represent on it (a) by the use of lines of 
suitable length and at correct distances apart, garden stuff 
sowed (or set) in rows ; (b) by the use of circles at correct 
distances apart that which is planted (or set) in hills. 
By the use of figures on these lines, and within these cir- 




Fig. 47. — String beans. Ready for 
household use, or for a lesson in 
botany. 



THE HOME SURROUNDINGS 



105 



cles, refer to a numbered list at one side of your sheet that 
names the kinds of stuff you would raise in your garden. 

7. Name both advantages and disadvantages (a) from 
alternating rows of corn and of potatoes ; (b) from having 
squash or pumpkin planted in among 

the corn. 

8. Why is it undesirable to have 
trees, shrubs, or bushes in the garden 
space? What small fruits may easily 
be grown out at one side of the garden ? 

TREE PLANTING 

1. Have you ever helped plant a 
tree ? What kind of tree did you plant ? 
Was it for shade, or for fruit bearing? 

2. In your locality what are good 
kinds of trees to plant for shade? 
Where may these be obtained ? About 
what is their cost per tree? What is 
a good choice of shade tree for planting 
as to (a) age ; (b) diameter ; (c) height ? 
Why not use older and larger trees for 
transplanting? In what respects is it 
generally better to purchase trees that 
have been grown in a local nursery 
than to get them from a distant part 
of the country ? 

3. Why will the growth of a newly set tree necessarily 
be slow at first? In order that food material for the 




Fig. 48. — Before set- 
ting out a young tree, 
its top and roots 
should be cut back 
as indicated by the 
dotted lines. The 
top will then have 
the appearance shown 
in a. 



106 LABORATORY LESSONS IN GENERAL SCIENCE 

growth of plants can be taken in through the roots, in what 
condition must this material be ? 

4. That the young tree be well nourished from the first 
after transplanting, (a) what form of root is desirable ; (b) 
what should be the condition of the soil filled in around the 
roots ; (c) why pour water about the roots, and w T hat amount 
should be used; (d) why press the earth firmly about the 
roots ? 

5. Why is such great harm done in an exposure of the 
rootlets to air and sun even for a very short time? While 
the planting of trees is going on, how may the roots of those 
awaiting planting be kept from injury? What purpose is 
served by leaving two or three inches of top soil loose and dry 
around each tree planted? What is meant by "heeling in" 
trees for later planting ? 

6. In what manner may young trees newly set be pro- 
tected (a) from ill effects of heavy winds ; (6) from animals ? 
Why is it harmful to the young tree (a) to break off its 
branches; (6) to pull it about, loosening it in the ground? 
Why is it harmful to tramp the soil about the tree by run- 
ning over it ? 

7. What is the chief use of leaves to plants? In trans- 
planting trees why is it generally best to trim off almost all 
side branches, and to cut back the top ? When does a young 
tree become able to provide for much leaf surface? What 
is transpiration in plants? 

8. Where a young tree is to be grown for fruit-raising, 
what shape of top is desirable ? Why so ? Why is it better 
to prune a little every year and not at long intervals ? Why 



THE HOME SURROUNDINGS 



107 



is there need to give more attention to pruning when the 
trees are young ? Why should the branches be cut off close 
up to the trunk (or main 
limbs) ? 

What different manner of 
trimming is followed when 
trees are for shade ? What 
is the effect upon the tops 
of trees when they are set 
too close? 

9. What are common 
causes for transplanted trees 
dying (a) when young; 
(6) when grown large ? Of 
what advantage to trees is 
it to have the ground under 
them mulched by leaves, or 
shaded by some growth? 

10. Read the poem "Planting of the Apple Tree" by 
Whittier, and memorize at least one stanza. 

TREES OF THE NEIGHBORHOOD 1 

1. The elm is so common a tree that it is well known 
generally. Its characteristics, too, are well marked. De- 
scribe the location briefly but definitely of a large elm grow- 
ing in your neighborhood. Tell where several others, large 
or small, are to be found. 

2. Name differences in the appearance of the bark (a) 
on older and on younger trees ; (b) on their twigs and on the 
trunks. 

1 See footnote of lesson on Temperature Records. 




Fig. 49. — How to prune trees. 



v-t-V fii '< 



108 LABORATORY LESSONS IN GENERAL SCIENCE 

3. Does the main stem of the elm usually continue up- 
ward through the tree top or subdivide into large limbs? 
Is the growth of small twigs (the "spray ") usually scanty 

or abundant ? What bearing has 
this on the elm as a shade tree ? 
In general are the outer branches 
rigid or drooping? 

4. From a study of elm leaves l 
state (a) w r hether the leafstems 
(petioles) below the broad blades 
are long or short ; (6) what the 
general shape of the blade is; 
(c) what kind of margin the leaf 
has ; id) what difference there is 
in the feeling of the upper and 
the low r er surfaces ; (e) what is a 
noticeable characteristic of the two sides of the blade; 
(/) just how the leaves are arranged along the stem. 

5. After an examination of the buds on some of the small 
branches of the elm tree, state (a), their relative locations on 
the stems, and their location with reference to the places of 
leaves (or leaf scars) ; (b) their general form ; (c) what their 
outer covering is, and what is found w r ithin the bud. 

6. Pick out elm seeds from a mixed lot of seeds of trees, 
and examine them closely. Make a drawing of a cluster of 
elm seeds. 

Learn the appearance of the flowers of the elm tree (from 
pictures if necessary). State their location on the stems with 
reference to the leaves. Be on the lookout in the springtime 



Fig. 50. — A tree in winter. 



1 Use good cuts in books if necessary. 




October 18th. 

Fig. 51. — Elm twigs, buds, flowers, and leaves. 

109 



110 LABORATORY LESSONS IN GENERAL SCIENCE 

to recognize elm flowers, and be sure to verify what is shown 
in the pictures. 

7. To what uses is elm wood put other than for fuel? 
What is its relative value for lumber? Discuss how the 
cutting of the forests of the United States has contributed 
to the high cost of living. 

8. Arrange alphabetically in a column a list of five or 
more shade trees known by you. In like manner mother 
columns, write (a) the names of five fruit trees ; (6) the names 
of five trees of which you have read or heard, but which 
otherwise are unknown to you. 

9. After such instruction as may be needed in the use of 
the "Key" in Farmers' Bulletin No. 468, make use of your 
copy as you come and go outside school to verify your list 
of shade trees, employing it with different trees of the same 
kind till you are perfectly familiar with the distinctions it 
makes. 

State what you have noted of different trees of the same 
kind as to form and general appearance even when age and 
conditions of growth are much the same. Note, too, that there 
are varieties of the same hind of tree, e.g., there are several 
different kinds of elm with marked characteristics that in- 
variably distinguish them. 

10. In a tabulated form suitably arranged under appro- 
priate headings, write in lines opposite each of the five shade 
trees named in paragraph 8 the characteristics of each 
kind of tree. (Write lengthwise of the page, and so that 
the same items for all trees fall in the same column.) This 
makes it possible, by following down a column, to note the 



THE HOME SURROUNDINGS 111 

differences among these trees in any one respect. In an ele- 
mentary way this grouping of facts is a "Key" for the 
identification of these trees. 

11. Outside of school hours make a sketch of some one of 
the shade trees you named, showing its form and manner 
of branching. State (by map or otherwise) just where this 
tree is to be found. Hand in the sketch. 

Using the Key of Farmers , Bulletin 468, and any available reference 
books on trees, determine the name and variety of a large number of 
trees in the immediate vicinity — trees which before were unknown to 
you. Cultivate the acquaintance of these trees till you are sure of 
recognizing them at sight, and have an interest in their growth and 
well-being as friends of yours. 

Be prepared to state in writing (as an examination for school credit 
it may be) the name and variety of any designated tree or trees of the 
neighborhood, together with the characteristics upon which you base 
your decision. (Be sure to include in your studies some of the ever- 
greens and ornamental trees of the vicinity.) 

SOME PLANT STUDIES 

1: Note the general form of the roots of some corn plants 
unearthed from flower jars in which they have been growing 
in the room. 1 Flatten one of the best of these specimens 
against white cardboard, and make a drawing to represent 
its appearance. The roots of the grasses and of the grains 
are very generally of this fibrous type. Gardeners, florists, 
and nurserymen in many instances transplant trees, shrubs, 
and other plants for the express purpose of causing them to 
form a large mass of fibrous roots. 

1 Provision for these studies must be made ahead of the time set for this 
lesson. 



112 LABORATORY LESSONS IN GENERAL SCIENCE 



2. Select a good specimen of long scarlet radish (likewise 
grown in the room), and make a drawing of it as an illustra- 
tion of a taproot. The root of the dandelion is of this form, 

and trees that have 
never been trans- 
planted may have one 
or several such main 
roots. Plants with 
taproots are likely 
to become strongly 
embedded. 

3. What is the 
general purpose (a) of 
the roots of plants; 

(b) of their stems ; 

(c) of their leaves? 
What may be con- 
sidered the primary 
purpose of flowers 
and seeds? 

4. Examine some 
stems (stalks) of corn 

and of the grains, and compare their structure with that 
of some young growths of trees or shrubs. Examine some 
vigorous shoots of last season's growth of various trees 
(a) for arrangement of leaves (or leaf scars) on the stem, 
noting whether it is alternate, opposite, or whorled; (b) for 
places of the buds with reference to these leaves. Some 
stems are climbers, as the hop plant, morning glory, etc. ; 
others are creepers, as the* strawberry. The common 




Fig. 52. — Taproot of the dandelion. 



THE HOME SURROUNDINGS 



113 



potato is an underground stem known as a tuber, and its 
"eyes" are buds from which new potato plants will grow 
as "sprouts." 

5. Out of a supply of leaves brought into the room by the 
teacher select specimens to illustrate parallel-veined, feather- 
veined, and palmately-veined leaves. 1 Make drawings of 
each kind. 

6. Make drawings of leaves that are (a) simple; (b) 
palmately compound and pinnately compound. (Pinnate = 
feather-like.) 

7. Make drawings to show leaves whose margins are 
entire, toothed, and lobed, choosing under direction of the 
teacher the best specimens at hand. 

8. Write in a column a list of four kinds of leaves repre- 
sented in the supply of fresh leaves at hand (or of mounted 
specimens). At the right of each such leaf-name write a 
single descriptive word under each of the following head- 
ings, so arranging these descriptive terms that they fall into 
columns thus : — 





Name of 
Leaf 


Veining 


Margins 


Kind (if 
Compound) 


Arrangement 
on Stem 


Kind of 

Surfaces 


1 

2 
3 
4 


— 


— 


— 


— 


~ 


— 



1 See illustrations in Botany texts, and other books. 



114 LABORATORY LESSONS IN GENERAL SCIENCE 




Fig. 53. — Type forms of leaves. 



THE HOME SURROUNDINGS 115 

BIRDS ABOUT OUR HOMES 1 

1. Make a list of ten birds that are so well known to you 
that you recognize them and can name them at sight. 

2. Name the several particulars in which these birds of 
your list are alike — those features of build, covering, ac- 
tivities, and manner of life that are common to all. In what 
respects do they all differ from domestic fowls such as the hen ? 

3. Tell what there is characteristic of any four of the 
birds named whereby you identify them. (Include details 
of their nesting, rearing of young, migrations, relations to 
men and to other birds, their songs, and the differences in 
plumage of male and female.) 

4. Make another list of birds known to be more or less 
common in your neighborhood but not recognized by you 
at sight with certainty. Underscore the names of any in this 
list that you think you might be able to call by name if 
you should see them. 

5. Select one bird from your first list and write a brief 
description of it, setting forth its characteristics in a way 
that would materially assist another person in recognizing 
the bird. 

6. Make another list of birds whose names are familiar 
but which you would not recognize at sight. Group these 
names into (a) those of the region where you live ; (b) those 
of foreign parts. 

Two weeks before the close of this work in General Science hand in 

a list of the birds that you have learned to know between now and then, 

telling when and where you have seen them, and upon what they seemed 

to feed. 

1 See footnote of lesson on Temperature Records. 



XI. LOCAL INDUSTRIES 
SOME OCCUPATIONS OF THE COMMUNITY 

1. Name a carpenter whom you know. Tell something 
of the work he does. Of whom does he get lumber for his 
work ? Name several people in town who are (a) carpenters ; 
(b) lumber dealers. Why are there fewer lumber dealers 
than carpenters? How much does a carpenter get for a 
day's work? How does a lumber dealer get paid for his 
time and labor ? What sooner or later is the business result 
when a lumber dealer cannot sell his lumber, or sells it for 
less than cost? Name some differences between making a 
living by working at a trade and by engaging in business. 
At what time of year is a carpenter likely to be out of work ? 
What expenses may a lumber dealer have when there is no 
business for him ? 

2. Whence comes the lumber that the dealer sells? 
How is it brought to him? From what is lumber made? 
Why do we not get lumber nearer home just as we get hay 
and corn? What will be done when the supply of lumber 
from the sources named is exhausted? What difference in 
the cost of lumber will this cause ? Give several illustra- 
tions of other material that is already substituted for wood. 
In what other ways is the timber supply of the country being 
conserved to some extent? What are the special duties of 
the Forest Service of the United States ? 

116 



LOCAL INDUSTRIES 



117 



3. Who in your community are railroad men, i.e., in 
the employ of the railways? Name others who are em- 
ployed in conveying freight, express, and people to and 
from the station. What would be true of the business of 
these men if there were no railroad into town ? What besides 
lumber is shipped as freight into your town by railroad? 




Fig. 54. — An artificial waterway. 



What other means for freight transportation have some 
towns? Name a place having transportation facilities not 
possessed by your town. How is the size of towns affected 
by having ample facilities for transportation? Why is 
this so ? 

4. What other supplies are commonly handled by the 
lumber dealer? Where does he get them? How r are they 



118 LABORATORY LESSONS IN GENERAL SCIENCE 

brought to him ? Why are they brought so far, and at such 
cost? Who determines what the freight charges shall be? 
What is involved in the determination of what is a fair and 
reasonable charge? Why does not every man bring in his 
own supplies ? Why are not competing lines of transporta- 
tion established to lessen freight rates? How is it that 
inland waterways regulate freight rates? 

5. Name other lines of business that furnish the car- 
penter supplies (a) for building purposes; (b) to live 
upon. Name several men you know engaged (a) in trade 
(business) ; (b) in agriculture. In this latter case name 
some of the various kinds of farm work carried on by them. 
Why does one farmer raise corn and alfalfa and hogs, and 
another keep cows for butter-making ? 

6. Under the heading " Agriculture' ' make a list of the 
occupations in which men engage that have to do directly 
with farming, such as stock-raising, fruit-raising, dairying, 
gardening, general farming, etc. Underscore those that are 
followed in the community round about you. 

7. Make a list of the industries other than trades and 
agricultural pursuits represented in your community. 

8. Make a list of the various trades, such as blacksmith, 
mason, etc. 

9. Name the professions represented in your town, — 
lawyer, physician, etc. 

10. List other occupations of men, — dentist, grocer, milk- 
man, printer, etc., grouping them under one or the other of 
the headings "Producers/' or "Consumers." State wherein 
some who are classed as consumers are to an extent pro- 
ducers, and those classed as producers also are consumers. 



LOCAL INDUSTRIES 119 

11. Name several occupations in which women are en- 
gaged outside the home in earning a livelihood. In what 
respects does successful management of household affairs 
demand higher intelligence of a woman than shop or office 
work ? In what respects must the housewife exercise a high 
degree of business ability in expending that part of the 
family income used to meet the cost of living? 

12. Give arguments against child labor in community 
life. Why is it desirable to have some employment, 
either indoors or out, for children at home? Name some 
home duties for which children may assume responsibility ? 
Wherein may there be educational value in such duties ? 

MODERN INDUSTRIAL LIFE 

1. Explain the fact that the shoemaking industry, for 
example, is centered in a relatively few localities, with a 
daily output of thousands of pairs of shoes for a single factory, 
rather than in small establishments scattered all over the 
country. Where must the people live who are engaged in 
any such industry? What is the effect of these conditions 
upon the distribution of population in the country as a 
whole ? 

2. Compare the advantages enjoyed by people who move 
to centers of industrial life with those commonly experienced 
in the more sparsely settled rural communities. Name some 
of the disadvantages to a wage-earning people incident to 
life in excessively congested quarters. What are some of 
the reasons that lead to the crowding together of different 
industries in a small district of a city instead of choosing 
locations more widely scattered? 



120 LABORATORY LESSONS IN GENERAL SCIENCE 

3. What relation is likely to exist between any chances of 
advancement in position for a wage earner, and his educa- 
tional and industrial preparation for his work? What 
conditions mav overrule this natural association? Name 




Fig. do. — When work hours are over. 



some factors, wholly apart from the efficiency of the individ- 
ual worker, that enter into the computation determining 
the pay that can be given employees in an industrial concern. 

4. How large a part has any one person in the making of 
a shoe, or the making of an engine ? Of what character, is 
the work of a shop or factory operative generally ? What is 
the effect upon a person mentally and physically who is 
engaged day after day as an attendant upon a machine ? 
What different results may follow the use of machines by 



LOCAL INDUSTRIES 



121 



skilled mechanics, professional men, builders, engineers, 
and others to facilitate the execution of any undertaking? 

5. Why should years of regular attendance at school 
contribute much towards keeping persons who operate 
machines masters of their labors rather than slaves to the 




Fig. 56. — One person can supervise many machines in the spinning room 
of a cotton factory. 



machine? How is it that much attendance at schools may 
sometimes fail to make a person an efficient worker in life's 
affairs? In addition to the information one may have 
acquired, what is characteristic of a person who is really 
"educated"? 



122 LABORATORY LESSONS IN GENERAL SCIENCE 

SANITARY CONDITIONS FOR THE WAGE EARNER 

1. From personal knowledge, or as you have heard the 
facts told, write an account of the hardships that have be- 
fallen some family by reason of accident, illness, or other 
disability directly traceable to conditions of employment or 
to the culpable negligence either of the individual or of his 
employer. Observe in a general way the following condi- 
tions for the narrative : — 

(a) Confine yourself quite closely to known facts, and 
discriminate between what is more important and what is 
incidental. Avoid setting forth as facts things only sur- 
mised to have been true, or that are merely the opinions of 
yourself and of others concerning the case. 

(6) Indicate obvious measures to be taken by the em- 
ployer and by the employee for the prevention of further 
cases of the kind. 

(c) The name of the person of whose case you write is 
unnecessary. Speak of Mr. A if you desire. Have in mind 
the hardships and losses not only of the individual but of 
the family and community as well. 

2. In the list of employments given below, injury to the 
workers is likely to occur unless special precautions are taken 
to remove dust-laden air. Copy the list, and to it add three 
other industries in which dust is a menace to the health of 
the workers. 

tool grinding cotton spinning flour making 

sand blasting wool finishing foundry work 

3. In what ways is danger to health from dust in factories 
and shops lessened or entirely eliminated? How is it that 
long-continued breathing of dust-laden air, otherwise pure 



LOCAL INDUSTRIES 123 

and free from germs, leads finally to tuberculosis ? What is 
the relation between warfare upon tuberculosis, and the 
prohibition of spitting on sidewalks and on floors of mills 
and factories? In what sense does the statement that 
"society has the right to protect itself" apply here? In 
matters of contagious diseases what is done to protect people 
generally ? What may very properly be done with those who 
at school and elsewhere wilfully and persistently refuse to 
regard the rights and welfare of others in matters of health 
and decency ? 

4. In what very true sense is the school a workshop ? A 
good schooling should give what advantages to anyone 
when seeking employment at any time ? What besides good 
health and physical endurance is desired of those who in 
office, shop, and factory are put in charge of complicated and 
expensive machines, and are called upon to use time and 
material to the very best advantage? Aside from skill in 
workmanship, what is meant by "an intelligent workman" 
in any of the callings of life ? What is it for an employee to 
"take the initiative"? 

5. One of the purposes of attending school is to become 
more capable and more efficient in the affairs of life than 
would otherwise be possible. State some things in common 
between the study of science in school (with its requirements 
to master and use what may be learned from books, experi- 
ments, and the experiences of life), and the procedure fol- 
lowed by (a) the lawyer who undertakes any case at law; 
(6) the contractor who seeks to accomplish any large job ; 
(c) the housewife who desires to spend the family income most 
advantageously. 



XII. THE FARM, AND OUR FOOD SUPPLIES 

THE HEN 1 

1. Tell what kind of fowls you keep at home (if any), 
and their distinguishing characteristics in color, build, etc. 
How could you identify any hens of yours in case they were 
to get with a neighbor's fowls ? 

2. In what ways are chickens hatched? What care 
must be given little chickens ? What feed is used for them ? 
What other provision must be made for them ? What food 
do fowls get for themselves when running at large ? 

3. Do hens chew their food as we chew ours ? How is 
their food ground, and where ? Why is there no need for 
horses to eat gravel and bits of stone ? Does a hen have a 
tongue ? 

4. What reason is there to believe that hens can hear ? 
Where in the head are a hen's ears located ? Where are the 
nostrils ? How does a hen drink ? 

5. Do hens shut their eyes? What difference in their 
eyelids from ours ? (Watch for a third lid that moves side- 
wise over the eyeball.) 

6. Why do not hens fly as freely as do birds? Where 
are the wings attached to their bodies ? Where in the body 
are the muscles for flying? 

1 It may be possible to have in the room for a few days one or more fowls 
in a coop such as used at poultry shows. 

124 



THE FARM, AND OUR FOOD SUPPLIES 125 

7. Of what use to the hen are feathers ? Of what value 
are feathers for household uses ? How do hens keep clean ? 
What provision is made for new plumage? 

8. In what respects is the foot of the hen different from 
(a) the foot of a horse ; (6) a man's foot ? How many toes 
on a hen's foot? To what uses do hens put their claws? 
The part of a hen's leg above the toes (the part that is cov- 
ered with scales) corresponds to what part of the human 
body ? Why do not fowls fall off when asleep on perches ? 

9. What is the purpose of (a) the comb ; (b) the wattles ? 
What significance in their changes in color? 

10. Explain differences in color in chicken meat. 

EGGS 

1. Remove the shell from an egg that has been boiled 
in some "Easter dye" solution. What is the significance of 



77-//nner albumen^ 
(white) 




^^"g^^r^"^^^ OR l/ES/CLE 


TH/CKER ALBUMEN--^ 




fmintkS^^- % 


(wh/te) / 

CHALAZA" > 


/ ywM Jill ^ \ % DARK yOLK 

/^^ m UGHT YOLK 


CONCENTR/C LAYERS- 




______ 1 /L^^^ OUTER MEMBRANE 


INNER MEMBRANE^ 




^^^ZZIlZr ^^\ y4/R SRACE 








Fig. 57. 


— The parts of an egg. 



any coloration through the shell ? Recall why canned goods 
do not spoil. What can be done to the shells to keep eggs 
for a long time ? What conditions favor the decay of all 
animal matter, including eggs? 



126 LABORATORY LESSONS IN GENERAL SCIENCE 

2. Carefully break a fresh egg into a clean sauce dish, and 
note (a) the germ, and its location ; (b) the light and dark 
parts of the yolk; (c) the chalaza (ka-la/za). 

Examine the large end of the broken shell for the air 
space, noting the membranes inclosing it. Infer if air can 
pass through these membranes. 

3. To a bit of the shell in a test tube add some strong acid, 
and describe the action. Note the effect of any escaping 
gas upon a drop of limewater. 

4. To a small piece of boiled white of egg in a dish add 
strong nitric acid; note any color change as the acid is 
warmed a little. 

Pour off the acid, rinse with water, and then add strong 
ammonia water. Describe any further color change. 

These steps and their results illustrate tests for the im- 
portant class of food substances known as protein (pro'te-in). 
The albumen of egg is but one of these. They are the tissue- 
building material of our foods. 

5. Observe closely, and state the results, as the teacher 
adds alcohol slowly to a little uncooked white of egg in a 
test tube, shaking the tube from time to time. 

POULTRY KEEPING 

1. Aside from profit what are good reasons for keeping 
a few fowls at one's home? Name some classes of people 
other than farmers who can profitably engage in the poultry 
business on a small scale ? What traits of character are quite 
essential in one who is to make a success of poultry raising ? 
What is a safe course for any one beginning to keep poultry ? 



THE FARM, AND OUR FOOD SUPPLIES 127 



2. Give arguments for and against making poultry rais- 
ing a sole business. What are the advantages of making it 
incidental to general farming ? 

3. What are the advantages and disadvantages in keep- 
ing pure-bred stock ? 

4. What is the importance of keeping the poultry ac- 
counts in a businesslike way? 



VENTILATOR 



sSUMMER POSITION 
V 0F CURTAIN 




Fig. 58. — Cross section of a poultry house. 

5. What may be considered a good site for a chicken 
house with reference to (a) character of the ground ; (b) near- 
ness to the barn and stables? What preferably is (a) the 
kind of foundation for the house ; (6) the nature of the floor, 
and the care to be given it ? What covering should be pro- 
vided for the floor when it is of cement ? 

6. What provisions should be made (a) for keeping the 
chicken house clean ; (6) for extermination of lice and mites ? 
What uses have whitewash and coal-tar wash? How is 
" whitewash " prepared ? 



128 LABORATORY LESSONS IN GENERAL SCIENCE 

7. Discuss arrangements for warmth, for light, and for 
the ventilation of the chicken house. What provisions 
should be made for exercise by the fowls, and for dust baths ? 
Where should nests be placed, and what schemes may be 
employed to keep them clean? 

8. Make a diagram in some detail showing the interior 
of a chicken house. At about what cost may a substantial 
house for a flock of twenty fowls be built? 

9. In the hatching of chickens, what advantages (a) in 
setting hens; (b) from use of incubators f Describe in a 
general way the construction of an incubator. 

10. Where incubators are used, (a) what time is required 
for hatching the eggs ; (6) what per cent of the eggs are likely 
to hatch under favorable conditions ; (c) what care should 
be observed as to the temperature maintained, the supply of 
moisture for the eggs, and their turning and cooling ? 

11. How is the fertility of eggs to be determined after 
they have been a few days in the incubator ? How soon can 
this be done ? 

12. What arrangement serves as a chick nursery within 
the incubator? Of brooders, state (a) their purpose; 
(b) the manner of their construction ; (c) the rate of reduc- 
tion of temperature in them ; (d) their period of use. 

13. How often should little chicks be fed, and how much 
at a time ? 

14. In general, what care should be given grown fowls ? 
State the kind, and the relative cost of foodstuffs for hens. 



THE FARM, AND OUR FOOD SUPPLIES 129 

How can green feed be provided (a) in winter ; (b) as pas- 
turage in summer? How may exercise for the fowls be 
secured through a feeding scheme? What provision may 
be made for " picking material"? What provision must 
be made for drinking vessels, and for a water supply ? 

15. In the marketing of poultry and eggs (a) what advan- 
tage is there in direct sales to the consumer ; (b) what care 
should be exercised in grading the quality of the product 
sold? 

16. Name some diseases to which fowls are subject. 
What preventive measures should be employed? 

17. State the educational values possible for boys and 
girls (a) from school courses in poultry keeping ; (6) from the 
care of poultry at home. What relation may this school 
instruction in poultry keeping have (a) to community life ; 
(6) to exhibits at the schoolhouse, and at Fairs? 

THE HORSE 

1. Do you have a horse at home ? If so, why do you 
keep it ? (If not, why not ?) 

2. If a horse should get out of the barn some night and 
go away, how could the owner know it as his horse when it 
was found ? In what other ways might it be identified ? 

3. Why is it best to keep away from strange horses? 
How does your horse behave toward you? Why so? In 
driving, how do horses sometimes misbehave ? What makes 
them do this? Why do horses so seldom misbehave? 

4. Who else that you know keeps a horse? For what 
use ? What* kind of horse best serves (a) the man who 
delivers heavy loads of coal; (b) the livery man whose 



130 LABORATORY LESSONS IN GENERAL SCIENCE 

horses must go many miles a day ? Wherein do ponies differ 
from horses ? 

5. What do you feed your horse? How often do you 
feed it, and how much at a time? What changes of feed 
are sometimes made (a) winter and summer; (b) when the 
horse is working hard and when doing nothing? What are 
the present market prices (a) of hay; (b) of oats? What 
other care should be given a horse besides feeding and water- 
ing it ? Why is this needful ? What is true of the amount 
of feed a horse needs if kept in a warm rather than a cold 
stable in winter? What care should be given a horse if 
hitched outside on a very cold day in winter ? Why should 
a horse not be driven fast on cold days? 

6. When you drive your horse, how does it know where 
to go? Why do you not need to have bits in your mouth 
that you may go where you ought ? How does a horse know 
when to stop? To what part of the harness are the lines 
fastened ? Why should a driver not jerk hard on the lines ? 
In cold weather, how may the bits cause pain to the horse ? 

7. What is the checkrein of a harness ? Hold your head 
for a little time as the horse has to hold its head when checked 
up high. What is the feeling you have? 

8. Of what use in the harness are (a) tugs ; (6) holdbacks ? 
Against which part of the body does the harness rub most 
when the horse is drawing a heavy load? What care is 
necessary because of this? 

9. How does a horse show (a) that he is impatient; 
(b) that he is tired ; (c) that he cares for you ; (d) that he is 
afraid of you; (e) that he is afraid of something by the 
way ? When only should a whipping be given a horse ? 



THE FARM, AND OUR FOOD SUPPLIES 131 

10. Describe as well as you can the shape of the horse's 
head as compared with your own. Make on your paper a 
drawing of a horse's head. 

11. Where in its head are the eyes? Of what advantage 
to the horse is this location? 

12. Where are the ears placed ? What are some advan- 
tages from this position ? 




Carpal Bones^.- 
Metacarpal Bones ,: 



Fig. 59. — Skeleton of a horse. Note especially the arrangement of the 
bones in foreleg and hind leg. 

13. Watch the horse eat, and see how it gets food into its 
mouth. Why do we not need to eat in the same manner? 

14. Watch a horse drink, and then a hen. What about 
a hen's mouth is different from the mouth of a horse or of a 
man? 



•\ 



132 LABORATORY LESSONS IN GENERAL SCIENCE 

15. What is peculiar about a horse's foot, and by 
what name is it called? Why do we have iron shoes 
on the feet of a horse (a) in winter; (6) in summer? 
What harm results from keeping the same shoes on too 
long? To what part of our foot does the horse's hoof 
correspond ? 

16. Show in a sketch of the hind leg of the horse where 
the joints 1 are that correspond (a) to our ankle; (b) to our 
knee ; (c) to our hip. 

17. On what parts of the body of the horse is the hair of 
unusual length, and what are the names given these different 
long growths ? Of what use to the horse is the tail ? What 
care should be given the hair and skin of the horse ? What 
changes have you noted in the hair of the horse at different 
seasons? 

COWS AND THE DAIRY INDUSTRY 

1. Name several considerations that enter into the mar- 
ket value of a cow for dairy use. About what is the present 
value in your community (a) of common " grade" cows; 
(6) of "full-blooded" stock? 

2. How in general does care of the cow compare with 
that of the horse in matters of food, drink, shelter, and 
kind treatment ? 

3. In what respects is the foot of the cow unlike that 
of the horse ? ' What is a noticeable difference in their 
tails ? 

1 Notice horses from time to time till you can locate the place of each such 
joint. Note the places of the corresponding joints in the foreleg. 



THE FARM, AND OUR FOOD SUPPLIES 133 



4. Where are the horns with reference to the ears? Of 
what use are the horns ? Why is dehorning of cows so gen- 
eral in dairies ? 

5. How many teeth has a cow in each jaw? What 
takes the place of the front teeth in the upper jaw? Does 





Fig. 60. — Cuts of meat in a beef animal. 



1. Neck 

2. Chuck 

3. Ribs 

4. Shoulder 

5. Fore shank 



6. Brisket 

7. Cross ribs 

8. Plate 

9. Navel 
10. Loin 



11. Flank 

12. Rump 

13. Round 

14. 2d cut round 

15. Hind shank 



the cow in grazing bite off grass as does the horse ? W 7 hat is 
peculiar about a cow's way of eating hay and grass, and what 
is meant by a cow's "chewing the cud"? 

6. Describe the manner in which a cow lies down and 
gets up, comparing it with the way of a horse. 

7. Make a list of the various cuts of beef bought at the 
butcher shop, with the name of the part of the animal whence 
each is obtained. 

8. State briefly the processes of changing the hides of 
cows into leather. Explain why leather does not decay. 



134 LABORATORY LESSONS IN GENERAL SCIENCE 



9. What are various uses for (a) cow's hair; (b) the 
horns ; (c) the blood ; (d) the bones ; (e) the fat ? 

10. Name at least two different breeds of cows, and state 
in what respects they differ in (a) size ; (b) color ; (c) quan- 
tity and quality of milk given ; (d) beef production. 

11. Where a cow is kept for profitable milk production, 
what must be true (a) of the quantity and quality of feed ; 
(6) of the water supply; (c) of regularity in feeding and 
milking ; (d) of definite knowledge of the income and outlay 
for each animal ? 

12. Of what advantage is the use of the cream separator 
in dairying as to (a) amount of cream taken from the milk; 
(6) labor involved in the care of milk? In what ways has 
the general use of cream separators largely changed the 

industry of butter- 
making? What use 
does the farmer make 
of the milk from 
which the butter-fat 
has been separated ? 

13. What sections 
of country are espe- 
cially favorable for 

- Clean milk requires precautions at dairying as regards 
milking time. / \ i i 

(a) general character 
of the country for tillage ; (b) price of land per acre ; (c) dis- 
tribution of rainfall throughout the grazing season ; (d) near- 
ness to town and city as markets ? 

14. Even where milk is sold in stoppered bottles, how may 
the consumer be endangered by carelessness and ignorance 




Fig. 61.- 



THE FARM, AND OUR FOOD SUPPLIES 135 

(a) in the care of the bottles ; (b) at milking time ; (c) in the 
stabling of the cows ? 

15. Where only the butter-fat of milk is sold, what ani- 
mals may be raised to add to the profits of the dairy busi- 
ness? Why should there be a greater and ever increasing 
fertility for the dairy farm in contrast with the very common 
impoverishment of farms cropped year after year with corn, 
small grains, cotton, etc. ? 

SOME FOODSTUFFS 

1. Melt (or soften) a little butter, and put a drop of it 
on a piece of glazed paper (letter paper). What appearance 
is given the paper? What class of substances gives similar 
results ? What is the nature of butter ? Describe the steps 
in butter-making. Of what use is butter as a foodstuff? 
What are good reasons for its use with bread? 

2. What is oleomargarine? What are the claims for 
and against its use as a foodstuff? Why is there a heavy 
government tax upon oleomargarine ? What is " cottolene " 
and what are its uses ? Name other like compounds having 
a similar use. 

3. What conditions of temperature and of acidity are 
favorable for the best results in churning ? What is (a) but- 
termilk ; (6) lactone ? What is renovated butter, and why 
is it less in price ? 

4. Observe very closely the results as the teacher per- 
forms the following experiments, and tell in each case what 
is the distinction shown between real butter and its imi- 
tations : — 



136 LABORATORY LESSONS IN GENERAL SCIENCE 

(a) In a spoon heat in turn small pieces of each substance, 
stirring them with a match stick as they boil. Note which 
boils with much foam and which with much sputtering. 

(b) Note the differences in results as the substances are 
tested separately as follows : Put a small lump into a test 
tube one fourth full of milk, and heat till the lump is melted ; 
then stir the liquid with a long splinter of wood, cooling the 
tube under the faucet till the fat hardens. In one case 
the fat should collect in a mass that can be removed on the 
splint, and in the other cases it remains scattered in gran- 
ules throughout the milk. 

Summarize the results by which any one of these sub- 
stances may be identified with a reasonable degree of cer- 
tainty. 

5. What per cent of butter-fat should be present in 
milk ? What per cent of milk is water ? What preservatives 
have been most commonly used in milk? Wherein is the 
harm? What causes the souring of milk by natural pro- 
cesses? How is this ordinarily delayed in household uses? 

6. What is (a) condensed milk, and its especial worth; 
(b) sterilized milk; (c) Pasteurized milk? 

7. Observe results closely, and state what is noted as 
the teacher (a) adds to one fourth test tube of milk a little 
vinegar, warming and shaking till separation of curd and 
whey occurs; (b) tests some of the curd with nitric acid, 
and then with ammonia solution, for protein food material. 

8. Describe briefly the making of cheese. Mention 
various kinds of cheese, and the differences in their manu- 
facture. 



THE FARM, AND OUR FOOD SUPPLIES 137 

9. Name three food constituents of milk. By what 
means may each be separated from the others? Discuss 
milk as a perfect food for infants. 

10. Distinguish between (a) suet, tallow, and lard; 
(b) veal, mutton, and pork. What are the chief reasons for 
cooking meat ? 

11. What different means are employed to prevent decay 
in uncooked meats? In sausage made up in quantity and 
exposed for sale, (a) what preservative is sometimes used; 
(b) what is used as a "filler" ? 

12. What great advantages affecting our food supply have 
resulted from the canning of meats and fish? Why are 
there so many cases of ptomaine poisoning from chicken or 
salmon salad? When a can of meat is opened, what pre- 
cautions should be taken before the meat is eaten? What 
is the nature of ptomaine poisoning? 

13. What are the chief food constituents of lean meat 
(muscular tissue) ? What are their digestive solvents ? 
What are peptones f What is the nature of the digestion 
of fats ? 

14. What is the chemical nature of bone? Which are 
the chief foodstuffs providing bone-building material? 
How may the relative weight proportions of animal and 
mineral material in bones be quite readily determined? 
What use is made by the body of the "lime" in water? 

15. From what is soap made, and how? Give the nature 
of glycerine, and its uses. 



138 LABORATORY LESSONS IN GENERAL SCIENCE 

LESSONS ON CORN 

(a) Corn in the Field 1 

1. Measure the distance between hills of corn in a row, 
and then calculate the number of them in a row 16 rods 
long. Measure the distance from row to row, and calcu- 
late the number of rows in a width of 10 rods. Calculate 
the number of hills in an acre (160 square rods). With four 
kernels per hill, how many kernels are needed to plant an 
acre? 

2. Count the number of stalks in a plot nine hills each 
way. With three stalks 2 to the hill, how many stalks 
should there be in the plot ? What is the per cent of short- 
age (or excess) ? 

3. Count the number of ears in the plot of 81 hills. With 
one ear on each of three stalks 2 per hill, how many ears should 
there have been? What per cent of shortage (or excess) is 
found? How many ears shortage (or excess) is this per 
acre? How many bushels of ears in this, taking 100 ears 
per bushel as an average ? How much shelled corn ? What 
value has this amount of corn at the market price ? 

4. About what is the average height of the stalks? If 
any are broken down, at what places with reference to the 
joints (nodes) are the breaks? Where are the leaves at- 
tached to the stalks? What is the purpose of joints in the 
framework of our bodies? What is told of the corn plant 
by the varying lengths between joints ? 

1 In the autumn. 

2 Use four per hill for those varieties having relatively short stalks and 
small ears. 



THE FARM, AND OUR FOOD SUPPLIES 



139 




Fig. 62. — Struc- 
ture of corn- 
stalk. 



5. Cut a stalk crosswise, and notice where the woody 
fibers are closest together. Slit a stalk lengthwise, and com- 
pare the structure at the nodes and between 
them (internodes) . What is true of the rela- 
tive size and strength of a stalk at the joints 
and between them? What connection is 
there between the woody fibers of the stalk 
and the fibers {veins) in the leaves? How 
are the fibers arranged in the stalk relative 
to one another? How is it in the leaves? 
What diameter (and circumference) has a 
stalk of average size two feet above the ground? 

6. About how high on the stalks are the ears ? What is 
the length of the ear stem ? What would be one disadvan- 
tage in having (a) the ears too high up ; (b) the ear stems too 
long? Where are the ears with reference to the leaves? 
What change is there in the shape of the stalk where the ear 
is? How are the leaves arranged on the stalk? When do 
corn leaves curl ? What is the cause of this curling ? What 
is the advantage to the plant in this ? 

7. Gather one of the largest and one of the smallest of the 
ears. What is true of the size of the stalk on which each 
grew ? What is the number of stalks in each of these hills ? 
What seems a good number of stalks for a hill, and what is 
the best relative size of stalk? 

8. Uproot one or more hills, and describe the general char- 
acter of the roots. What special use have the "air roots" 
of the corn? To about what depth did the corn roots 
grow? What relation has this to the depth to which the 
soil should have been plowed? How far sidewise did the 



140 LABORATORY LESSONS IN GENERAL SCIENCE 



roots reach out? What bearing has 
this on a late cultivation of the crop ? 
9. Select a good ear and carefully 
remove its husks. If the stem bear- 
ing the ear were greatly extended 
outward, to what would these husks 
on this new stalk correspond ? Note 
to what each of the threadlike silks 
is attached at its inner end. Observe 
in other ears whether the silks extend 
outward beyond the husks. Where 
on the cornstalk were other blossoms 
that bore stamens and an abundance 
of pollen grains? What is true of 
the times of appearance of silks and 
"tassels''? How will it affect the 
crop if the weather at such a time 
Fig. 63. — Roots of the is very hot and dry, or too wet and 

corn plant. , , 

cold : 

(b) A Study of Ears of Corn 

1. Count the number of rows of kernels on an ear of me- 
dium size, and the number of kernels in one row. Calculate 
the number of kernels per ear. How many ears are needed 
to plant an acre? (See paragraph 1, Corn in the Field.) 
How many bushels? (See paragraph 3.) Of the ear that 
you examine, state (a) if the kernels fill the ear entirely 
over the tip ; (b) if there are any places where kernels are 
missing ; (c) if the base of the ear is large and well filled out. 
State whether the kernels are crowded close together on the 
cob, and whether they are of uniform size and shape. 




THE FARM, AND OUR FOOD SUPPLIES 141 

2. Choosing what you consider the best ear, find the cir- 
cumference at one third its length from the base. Calcu- 
late the ratio of this circumference to the length of the ear. 
Break the ear at about its middle and determine the ratio 
(a) of the diameter of the cob to the diameter of the ear; 




Fig. 64. — Specimen ears of different varieties of corn. 

(6) of the area of the broken end of the cob to the broken end 
of the ear. 1 

3. Get a good ear of cured (old) corn and find the ratio of 
the weight of the cob to the weight of the ear before it was 
shelled. 

4. Somewhat at length, and very specifically, state the 
characteristics of the best ears of corn. 

1 The areas of circles are to each other as the squares of their diameters. 



142 LABORATORY LESSONS IN GENERAL SCIENCE 

5. What advantage is there (if any) in having the ker- 
nels wedge-shaped? State if there is any dent in the large 
end of the kernel. What differences are there in the sides 
of a kernel? With a knife remove the thin outer coating 
of a kernel (its hull). Note where the color of the kernel 
seems to be lodged. At what place in the hull is a hole 
found? What is its probable purpose? 

6. Examine some kernels that have been in water for two 
or three days, and away from the light. What change has 
occurred in the size of the kernel, and of the groove in its 
side? Having removed the hulls, cut some of the kernels 
lengthwise along the groove, and others lengthwise but at 
right angles to it. Observe the little embryo in each case. 
The large portion of the kernel surrounding the embryo is 
the endosperm. 

7. Put several of the soaked kernels between blotting 
papers kept moist in a warm room for several days. Ex- 
amine the embryo, and infer what it is likely to become. 
Distinguish between its plumule and its radicle (root). Dis- 
tinguish any parts of the plumule, and of the root. Observe 
any hairlike rootlets, and tell where they are. The change 
which has taken place in the kernels is called germination. 
After corn is planted, to what extent can, conditions for 
germination be controlled? About how early in the Spring 
is it safe to plant corn in your section of country ? 

8. Fill a glass fruit jar with mellow soil that is somewhat 
moist (but not water-soaked). Push down into the soil 
next the sides of the jar where they can be seen several 
kernels that have been soaked for three days. Have them 
at different depths below surface. Keep the soil just moist, 



THE FARM, AND OUR FOOD SUPPLIES 



143 



the jar covered with a black cloth, and all conditions for 
germination favorable. Examine the jar daily till the best 
depths for planting seem apparent. Note any marked tend- 
ency in directions of growth of the plumule and of the rad- 




Fig. 65. — Results of planting at different depths (in inches) . 



icle. What is the number of leaves when the young plant 
comes through the soil ? What condition of the soil favors 
the outward growth of root and plumule? What prepara- 
tion of the soil is desirable before planting corn for a crop ? 
W T hat purpose is there in the cultivation of the soil at its 
surface only during the growing season ? 



144 LABORATORY LESSONS IN GENERAL SCIENCE 

(c) Corn Raising as an Industry 

1. What variety of corn is most commonly raised in 
your section of country? Name some other varieties. 

2. Tell how seed corn for another season should be se- 
lected. How should it be cared for after it has been gathered ? 
How is seed corn tested for its powers of germination ? 

3. Describe somewhat at length the manner of gathering 
a crop of corn. What determines the time for beginning its 
harvest? About how long a time is it from planting till 
the crop is ripe enough to be gathered? Why is the new 
crop often stored for a time in cribs? 

4. What machinery is employed in raising a corn crop? 
In harvesting it ? In marketing it ? In general, is the cost 
per acre of raising a large yield of corn likely to be much 
more than for a small yield ? Why so ? What expense items 
are likely to be greater? What are several advantages to 
the farmer in feeding his corn on the farm rather than sell- 
ing it ? As land values and the cost of labor increase, involv- 
ing need of larger capital to carry on successful farming, 
what is likely to become more and more true of the degree 
of business ability necessary to make farming a paying in- 
dustry ? 

5. Name a large number of the products of packing 
houses where corn-fed cattle and hogs are marketed. How 
very largely is this livestock brought to the packing houses ? 
How are the packing house products distributed to con- 
sumers? What would be the effect upon the number of 
men employed in these fields of industry if there should be 
a failure in the corn crop for a year or two? What would 



THE FARM, AND OUR FOOD SUPPLIES 145 










146 LABORATORY LESSONS IN GENERAL SCIENCE 

be the effect upon the manufacture and sale of farm imple- 
ments? Upon the purchasing ability of farmers for sup- 
plies ? Upon merchants and manufacturers ? Upon living 
expenses for the people of the country? 

6. From what you are able to learn by a visit to the near- 
est canning factory (or from books) briefly describe the steps 
in the processes of canning corn from the time the corn is 
delivered at the factory till the cans are packed in boxes for 
shipment. 

7. Of what use on the farm is a silo f Explain why great 
care must be exercised in its construction. What fodder is 
used for filling silos ? Of what special advantage to the dairy- 
man is the use of ensilage f What prevents the rotting of 
the material stored in the silo? 

8. Briefly retell the steps in the manufacture of corn 
starch as described in some reference book. Name some 
uses of starch in the home. 

9. What is glucose ? How is it made ? What uses has it ? 
10. Name some of the corn breakfast foods. In general, 

how are they prepared? In what other forms is corn used 
as a food for men? 

FRUIT AND APPLE RAISING AS AN INDUSTRY 

1. In a column write a list of the various fresh fruits that 
may be purchased at certain times during the year at fruit 
stands and grocery stores in your home town. Underscore 
the names of those grown in your immediate vicinity. After 
each of the names of the others write the country or section 
where it is grown for market. In a third column write the 
prevailing price for each fruit in season. 



THE FARM, AND OUR FOOD SUPPLIES 147 

2. Explain how it is possible to ship and market in good 
condition such perishable fruits as (a) bananas ; (6) berries. 
Name conditions that must be observed by shippers and 
fruit dealers generally so that a ready market shall be found 
for their fruit. Compare the keeping qualities of the orange 
and of other fruits in market. Account for any differences. 

3. If we accept the definition that a fruit is the ripened 
product of plant growth bearing the seeds of that plant, 
what so-called vegetables come into the list of fruits? Of 
what use are the seeds produced by plants ? Describe ways 
in which various plants secure the dispersion of their seeds. 
What is true with regard to seeds in the banana, and in some 
oranges? Describe the propagation of these fruits. Make 
a list of a half dozen plants that could be propagated without 
seed production by them, and state how this might be accom- 
plished. What would be true of plants generally if no seeds 
were to be grown for several seasons in succession? What 
effect on mankind would failure of plants to produce seeds 
have ? Give some examples to show this. 

4. Fresh apples when cut and exposed to the air soon turn 
brown. Why are evaporated apples so white? What is 
true of the relative degree of preservation of the flavor of 
apples when dried and when canned ? About what per cent 
of an apple is water? Account for the shriveling of apples 
kept in a warm basement. 

5. About what should be the age and size of trees to set 
out for an apple orchard? What is the cost of standard 
varieties of such trees at the nearest reliable nursery? How 
many years before apple trees are likely to bear fruit ? 



148 LABORATORY LESSONS IN GENERAL SCIENCE 



6. What does the nurseryman mean by " seedlings"? 
What has to be done with them in order to be sure of the kind 
of apple borne by the tree when grown ? Describe this pro- 
cess. Account for the different varieties of apples. How 

have these been improved? 
Why are crab apple trees 
often used as the " stock" 
into which the scions of im- 
proved varieties are grafted ? 

7. Describe a suitable 
preparation of ground for 
setting out an orchard. What 
care must be exercised with 
the young trees at the time 
of transplanting? What is 
the* best time of year for 
setting out apple trees in 
your section of country? 
About how far apart should apple trees be set ? Why not 
closer? Calculate the number of trees per acre (a strip ten 
rods wide by sixteen rods long) . In what ways may profit- 
able use of this ground be made in the years before the trees 
are large enough to bear fruit freely ? 




Fig. 67. — Grafting fruit trees. 



8. About how many bushels of marketable apples may 
be considered a satisfactory yield for a tree in full bearing ? 
That will be how many bushels per acre? At retail prices 
on the local market calculate the value of the crop per acre. 
After apples are sold from the orchard, what charges increase 
their cost to consumers ? 



THE FARM, AND OUR FOOD SUPPLIES 149 

9. About what time of year do apple trees blossom? 
What course is followed in large orchards to prevent loss of 
the season's crop by a late freeze in the spring? About 
when are the earliest varieties of apples on the market for 
eating? How is it that these kinds ripen so much earlier 
than some other kinds ? 

10. Does every blossom of the springtime yield an apple 
in autumn ? If this were so, what would be the results (a) in 
the size and quality of the apples; (b) for the tree itself? 
What course is pursued by some growers to get exceptionally 
fine fruit ? Why is this not done by all apple raisers ? 

11. What special care must be exercised in harvesting 
apples? Why are boxes preferred to barrels for the larger, 
finer fruit? Why does wrapping each apple separately in 
paper aid materially in its keeping qualities? Explain the 
nature of rot in apples. What is nature's protection of the 
apple from decay? Why do apples graded as to size and 
appearance sell more readily in market ? What is true of the 
relative selling prices of these apples and of others marketed 
by the barrel ? When apples are to be kept for any length 
of time, what should be true in the storage rooms (a) of the 
temperature ; (b) of the moisture in the air ? What uses are 
made of the apples that are undersized, misshapen, and worm- 
eaten? What other uses may be made of the "windfalls" ? 

12. Describe the spraying of trees in an apple orchard, 
stating the material used and the manner of its application. 
At what times in the year is this spraying done? In some 
way give a definite idea of the cost of doing this, including 
the labor. 



150 LABORATORY LESSONS IN GENERAL SCIENCE 



13. How is cider vinegar made ? How may this change be 
prevented, and the cider be kept sweet? What household 
uses has vinegar? How is apple jelly made? 

14. In apple raising on a large scale, why is there need 
(a) of good business ability ; (b) of considerable capital ? 
What degree of intelligence is required to make fruit-raising 
a success? 

WHEAT, AND WHEAT GROWING 

(a) In the Field 1 

1. About what height has the wheat 
plant as found in the field at the time of 
this lesson ? About what will be its height 
when ready for the harvest? What ad- 
vantages in the hollow growth of the 
stems as regards (a) the time that would 
be required for growth to the same size if 
solid; (b) the strength of a solid stem 
having the same amount of materials 

2. Examine a growing wheat plant to 
discover if every stalk is from a separate 
kernel sown. What is meant by the 
"stooling" of wheat? Note how far 
below surface the crown of the wheat 
root grows. What advantage is there 
to the plant growth in this? 

3. Dig carefully about a wheat plant 
-The "stool- and ascertain to about what depth the 

of grain. 

roots grow. 

1 Any field studies of growing wheat must of course be arranged to suit 
local conditions. See footnote under Temperature Records. 




THE FARM, AND OUR FOOD SUPPLIES 151 

4. Make drawings of a wheat plant as a whole, showing the 
roots, stem, leaves, and head. In what respects is the wheat 
plant much like the grasses grown for hay ? 

5. In case the wheat seeding was done by use of a drill, 
what distance is found (a) between rows ; (b) between plants 
in the row ? 

(b) In the Laboratory 

1. Uproot and examine some young wheat plants, grown 
in moist rich soil in flower jars in the room. Compare the 
vigor of growth of several of the plants in relation to the 
apparent size and plumpness of the kernels from which they 
sprung. 

2. Make drawings (a) of one of the wheat plants ex- 
amined ; (6) of a wheat head (full size) ; (c) of cross sections 
of a wheat kernel, both longitudinal and transverse. 

3. Side by side make sketches of the heads of two varieties 
of wheat to show clearly the points of difference. 

4. Count the number of grains rubbed out from a medium- 
sized head of wheat. Ascertain what per cent of those you 
obtain are plump and of full size. Calculate how many fold 
the wheat kernel from which your stalk sprung multiplied 
itself, allowing six stalks from one kernel. 

OTHER FOODSTUFFS 

(a) Starch 

1. Remove the outside of a kernel of wheat. Examine 
and describe its texture, and the character of the substance 
within the kernel. 



152 LABORATORY LESSONS IN GENERAL SCIENCE 

2. Into a piece of thin cotton cloth put a little bran, and 
knead it in some water in an evaporating dish so long as any 
milky liquid comes out through the cloth. Continue washing 
it at the hydrant till the water runs off clear. State the 
nature of what remains in the cloth, and of what has settled 
in the dish. From w r hich part of the wheat kernel does 
each come? 

3. In like manner knead some flour in a cloth. When the 
white solid has largely settled, pour off the water in the dish, 
and spread some of the solid on a filter paper to dry by 
evaporation. Crumble the dried solid later and state what 
it resembles. 

Heat some of this solid with a little water in an evaporating 
dish till the water boils. Wet a strip of filter paper in the 




Fig. 69. — Effect of cooking upon starch granules. Cells of raw potato are 
shown in a, and when cooked in b and c. 



solution, and let fall drops of iodine solution at different 
spots on the paper. Note the characteristic blue of the test 
for the presence of starch. 

4. In the same manner as in paragraph 4 under Eggs, test 
some of the gluten (substance left in the cloth from the flour). 
What is the result ? 



THE FARM, AND OUR FOOD SUPPLIES 153 

It is to be kept in mind that the protein of plant growth (such as 
gluten), and of the animal foodstuffs (such as albumen of eggs, casein 
of milk, the fibrin of meat), are principally tissue-building material, 
while starch and the sugars are chiefly body fuels. ' 

5. When to some baking soda in a test tube hydrochloric 
acid was added a little at a time (paragraph 4 under Car- 
bonates), what gas formed? 

Mix thoroughly a very little baking powder with a tea- 
spoonful of flour. Make a thick dough out of it with cold 
water ; knead it well with the fingers, and then bake it in a 
spoon. Explain the "rising" of the loaf. Why does the 
loaf retain its shape? 

6. Dissolve some baking powder in a little water and heat 
to boiling. Observe the character of the liquid when rubbed 
between the fingers, and infer its meaning. Wet a strip of 
filter paper in the liquid, and test with the iodine solution. 

(b) The Sugars 
■1. Describe all changes as the teacher cautiously pours 
concentrated sulphuric acid into some thick hot sirup of 
cane sugar in an evaporating dish. The sulphuric acid 
takes hydrogen and oxygen from the sugar (as H 2 0), leav- 
ing the carbon (C). 

2. Note the results carefully when a few drops of Fehling's 
solution are added to a solution of grape sugar (glucose, or 
corn sirup) in a test tube, and the liquid is heated to boiling. 

State the results when the same test is made (a) with a 
solution of cane sugar ; (6) with a starch solution. 

3. Crush and dissolve some samples of candies, and test 
for (a) grape sugar; (6) starch. State your results, and 
their significance. 



154 LABORATORY LESSONS IN GENERAL SCIENCE 

ORIGIN AND NATURE OF SOILS 

1. Examine specimens of quartz, feldspar, hornblende, and 
mica. Describe each with respect to its characteristic appear- 
ance. Be sure to take note of any differences in appearance 
of specimens of the same kind of mineral (usually due to ad- 
mixture of other earthy material). It is to be remembered 
that each of these substances in a pure state is a somewhat 
complex chemical compound of definite composition. After 
becoming familiar with these type specimens so that they 
are readily recognized at sight, identify any specimens that 
may be assigned you by numbers only. 

2. Examine specimens of several different kinds of granite, 
and be able to point out in them particles of quartz and 
feldspar, as well as any hornblende and mica (if present). 

Examine specimens of "weathered granite. " State which 
of the constituent minerals seems to possess greatest re- 
sistance to decomposition. 

Whether at the seashore or inland, and however exten- 
sive its amount, sand may be considered as quartz particles 
derived from granitic rock. Clay is feldspar decomposed. 
Explain how it is that clay and sand, possibly from the same 
rock sources, are frequently found as deposits entirely dis- 
tinct, and often widely separated. Account for sandstone 
as a rock. Explain why it is that sandstone so often exhibits 
a stratified form (an arrangement in layers) . 

3. Rub some dry clay between the thumb and finger. 
With a magnifying glass note in a general way the size of the 
clay particles as seen when scattered over the surface of white 
paper. 



THE FARM, AND OUR FOOD SUPPLIES 155 

Wet some clay in an evaporating dish, and then note its 
feeling and odor when rubbed between the fingers. Note 
the odor and feeling of shale and of slate when wet. 

SOIL CONDITIONS FOR PLANT GROWTH 

1. Recall (a) the definition of solution; (6) why sub- 
stances remain undissolved. Test the solubility of bits of 
crayon and of limestone (a) in water; (6) in hydrochloric 
acid. Explain any differences in their behavior. 

Whence comes the water in the sap of plants ? How is it 
possible for food materials in the soil to get into the plant 
for its use in growth and fruitage ? What change in a sub- 
stance in the soil must often precede its solution by the soil 
water ? 

2. Observe the surface of any piece of stone that has been 
dipped into water. Explain what is noted. If the stone is 
now broken into several pieces, and all these are dipped into 
water, what is true (a) of the extent of their surfaces now ; 
(b) of the amount of water clinging to these surfaces ? 

Break a blackboard crayon into piece after piece ; fit the 
several pieces together again, and then separate them anew. 
What is manifest as to the extent of exposed surfaces of the 
crayon before and after it is broken into pieces ? 

What would seem probable of the amount of exposed sur- 
face, and of the adhering film of water (film-water), if division 
of rock materials should be continued to the size (a) of sand ; 
(6) of dust particles? 

3. Have three test tubes about one third full and well 
settled by jarring, one with coarse sand, one with loam, and 
one with silt. Into each pour the same amount of water, 



156 LABORATORY LESSONS IN GENERAL SCIENCE 

enough to stand above the surfaces. Shake all well, let 
settle fully, and then drain off the water into separate dishes. 
Measure the amount of such drainage in each case. Ex- 
plain any marked difference. 

4. Put into a test tube a half inch of soil that apparently 
is dry, and heat it gently. Watch closely for any evidences of 
moisture in the tube as the heating is continued, and explain. 

Examine some soil that feels and looks moist. Just where 
in the soil is this water, and how is it held in place ? 

5. Weigh out several grams of apparently dry soil in an 
evaporating dish. Heat it gently, stirring all the time, and 




Fig. 70. — Rise of soil water by capillarity. 

be careful not to char or cause other change in it than to 
drive off any water in the sample. Weigh anew, and calcu- 
late the per cent of loss of moisture from the soil when dried. 

6. Let pieces of cheesecloth be tied over the small ends 
of three student-lamp chimneys, and have one chimney 
filled with sand, one with loam, and one with silt. Have 
the contents of the chimneys made compact by jarring. 



THE FARM, AND OUR FOOD SUPPLIES 157 

Arrange the chimneys so they are supported upright with 
their lower cloth-covered ends in a pan containing about an 
inch of water. 1 From time to time observe the upward rise 
of the water into the chimneys by capillary action, both its 
elevation and its rapidity of ascent. Account for any dif- 
ferences noted. 

As the water in the surface layers of soil in the field becomes 
exhausted by plant growth, or by evaporation, whence may 
it be replenished without rainfall, and how ? 

7. Counterbalance two baking powder cans that have 
been filled somewhat more than half full of moist soil made 
compact by jarring, the top of the soil in one of the cans hav- 
ing a half-inch layer of fine dry loam (or some dust). Ob- 
serve the scales from time to time through a day or two as 
they are left undisturbed. Interpret the significance of any 
loss of equilibrium. What relation has this to the cultiva- 
tion of crops during the growing season ? 

8. Watch closely for the escape of any bubbles of air from 
a test tube one half full of soil as an inch or more of water is 
poured in upon the soil, and account for the bubbles. What 
is a possible cause of the dying of plants in pots where any 
excess of water poured in cannot drain off. Account for a 
possible crop failure on low grounds in wet seasons. 

USEFULNESS OF PLANTS TO MAN 

1. From your own personal experiences, and from any 
other sources of information, prepare lists of four items each 

1 Through the upper side of a box from which the front has been removed 
bore holes of a size such as to allow the small ends of the chimneys to pass 
and to hang suspended in full view. 



158 LABORATORY LESSONS IN GENERAL SCIENCE 

(a) of substances used in houses for fuel and lights; (6) of 
foods eaten uncooked; (c) of food material prepared for 
table use by cooking in the home kitchen; (d) of canned 
goods ; (e) of drinks other than water ; (f) of raw materials 
for clothing; (g) of articles of furniture; (h) of materials 
having large use in building houses. 

In these lists underscore the names of all those substances 
derived directly or indirectly from plants. (Be ready to 




Our next year's clothing. 



state in class just how this is in all cases where the origin is 
not clearly apparent.) 

2. Tell briefly but very definitely the dependence of people 
upon plants, and upon the products manufactured from 
them, in matters (a) of travel ; (6) of medicines ; (c) of live- 
lihood ; (d) of comforts of life ; (e) of pleasant surroundings. 



THE FARM, AND OUR FOOD SUPPLIES 159 

3. Name regions of the world where little or no plant life 
exists, and state briefly the reason for each such case. What 
is true of animal life there? What food supplies are avail- 
able there for men? What material is to be had there 
(a) for dwellings ; (b) for clothing ? 

As an example of the usefulness of plants to man, gather by reading 
and from all available sources as full information as possible of the 
plants from which the crude rubber is obtained, the processes in- 
volved in their cultivation, the harvest and preparation of this material 
for market, and its processes of manufacture. 

4. Under appropriate headings, make lists of the various 
manufactured articles into which rubber enters for use in 
modern life. 

5. State very definitely the processes of rubber manu- 
facture from the crude gum of the rubber fields. 

6. Tell briefly of the care and cultivation of the rubber 
plantations, and of the general character of the regions that 
are the chief sources of rubber supply. 



XIII. WORK AND MACHINES 

MEANING OF THE TERMS WORK AND ENERGY 

1. Hold a book out at arm's length for a few minutes. 
What sensation is noticeable in your arm after a time? 
Regardless of the fatigue and exhaustion experienced in 
this exercise, it is only when motion occurs in bodies, 
or in the particles composing them, that the term work 
as used in Physics is applicable. There was work done 
in changing the position of the book but not in holding it 
in place. 

2. Why do the muscles of the body become tired (fatigued) 
through exercise when at labor or play ? Do machines such 
as the steam engine become weary when at work? What 
does result in them from continued use? 

3. Name several changes in bodies caused by the action 
of forces upon them. In which of these cases is work done, 
and why so ? 

4. What is the basis for a belief that there is any such 
force as gravity? How does an intending purchaser of 
a horse assure himself that the animal has sight (good 
vision) ? What is the meaning of the term theory as used 
in science, and in the affairs of life? What must be true 
of any belief, opinion, or theory if we are justified in con- 
tinuing to cherish it ? When must a theory be modified or 
rejected ? 

160 



WORK AND MACHINES 



161 



MEASUREMENT OF WORK AND ENERGY 

1. With a spring balance lift some small body; note its 
weight in pounds (and sixteenths of a pound). This value 
represents not only the quantity of matter in the body, i.e., 
its mass (m), but 
as well the value 
of gravity as a 
force (/) pulling - 
down on the 
mass, and the re- 
sistance (r) over- 
come in lifting 
the body. In the 
measurement of 
work, as well as 
of the energy 
used in doing 
that work, one of 
the units em- 
ployed is the foot- 
pound. This is often defined as the amount of work done 
(and of energy used in doing it) when a force of one pound 
causes motion through one foot distance. State a correspond- 
ing form of definition for work when the term resistance is 
substituted for "force/' and the phrase is overcome takes 
the place of "causes motion." 

2. Calculate the number of foot-pounds done when the 
reading of the balance is 1^- pounds, and the distance the 
body is lifted is 16 inches (1^ feet). 




Fig. 72. — Work is the " overcoming of resistance." 



162 LABORATORY LESSONS IN GENERAL SCIENCE 

3. Drag the same body along the table through the same 
distance of 16 inches, and as accurately as possible get the 
balance reading for the resistance overcome (and of the force 
used in overcoming the resistance) . In calculating the work 
now done in moving the body, why is it not the same amount 
of work as before? 

4. Calculate anew as in paragraphs 2 and 3 above, but 
this time take the balance readings in grams for whatever 
body is used, and let the distance moved be in centimeters. 1 
Let the product of the weight (force, or resistance), and the 
distance (or space), be gram-centimeters of "work" (or of 
"energy" used in doing the work). 

5. Express the number of grams above as kilograms, and 
the number of centimeters as meters. 2 Then calculate the 
amount of work done in kilogram-meters. 

CLASSES OF LEVERS 

1. By means of a lever clamp support a meter stick at 
its middle point. Using loops of string over the ends of the 
meter stick, support any small weight near one end, and 
pull down sufficiently on the other end with a spring balance 
to keep the bar (lever) horizontal. Move the weight (W) 
to different distances from the point of support or fulcrum 
(F), and in every case note and record both the balance 
reading (P) and the distance from P to F. For several of 
these positions of P and W get the product of P X Pd 
(power-distance), and of W X Wd (weight-distance). These 

1 Balances and rulers should have both metric and English scales. 

2 One kilogram = 1000 grams, and one meter =100 centimeters. 



WORK AND MACHINES 163 

products are the moments of P and of W. Infer when a 
lever will be in a balanced condition, or state of equilibrium. 
Make a drawing that shows the lever in some one of these 
positions, and correctly locate on it the positions and values 
of P and W. Label the drawing 1st Class Lever. 

2. Having the lever supported as before, put both P and 
W on the same side of F, and with W between P and F. It 
will now be necessary to pull upward with the spring balance 
in order to maintain equilibrium. Calculate the moments 
of W and of P in different positions, and state what is 
true of their relative values in every instance. What 
is true in every case (a) of the relative lengths of power 
and weight arms (distances) ; (6) of the relative values 
of Pand W? 

Make a drawing to represent the lever in some one of 
these positions, and label it 2d Class Lever. 

3. Arrange the lever now so that the pull of the balance 
(P) is upward, and between W and F. State what is found 
true under these conditions (a) of the moments of P and W ; 
(6) of the relative values of P and W. Make a drawing to 
represent a 3d Class Lever, putting upon it the values 
found in some one of the cases for P and W, and for Pd and 
Wd. 

PULLEYS 

(a) With the Cord Attached to the Fixed Pulley 

It is desirable to have a pair of "triple-tandem" pulleys as rep- 
resented in the cut, and a spring balance graduated both in grams and 
in ounces. A length of stout, smooth cord with loops at its ends is 
easily provided. 



164 LABORATORY LESSONS IN GENERAL SCIENCE 

1. Make two freehand drawings on your paper similar 
to the cut, showing in the first one movable pulley in use, 
and in the second two movable pulleys. In all cases repre- 
sent one end of the cord attached to the fixed pulley. 




Fig. 73. — Diagram of pulleys. 



2. Let the teacher fit up pulleys in turn representing 
these same conditions, and determine by use of the spring 
balance in each case (a) the value of the resistance overcome 
(i.e., the weight of movable pulley and its attached body x ) ; 



1 Any friction, or resistance other than gravity, is disregarded here. 



WORK AND MACHINES 165 

(b) the effort put forth ("pull" exerted) to lift the body. 1 
Enter on your drawings the values found by the teacher, 
marking the resistance as W (weight), and the effort as P 
(power). 

Be sure to verify the correctness of your drawings by 
reference each time to the pulley arrangement as set up by 
the teacher. 

3. Let the teacher take the readings of the spring balance 
for the value of P (a) when pulling down over the last of the 
fixed pulleys; (b) when lifting up, and not using this last 
fixed pulley. Infer (a) the only purpose of this fixed pulley ; 
(6) whether the section of cord for pulling downward shall 
be counted in any case as a supporting cord for W. 

4. From inspection of your diagrams, and of the values 
of P and W shown thereon, state what appears true (a) of the 
number of cords supporting W relative to the number of 
movable pulleys ; (6) of the fractional part of W supported 
by each cord; (c) of the ratio (approximately) of W to P 
relative to the number of such cords. 

5. Measure the distances through which P moves in all 
of the cases above when W is raised through a distance of 
one foot every time. State for each case how many times 
greater the power-distance (Pd) is than the weight-distance 
(Wd). How does this compare with the number of support- 
ing cords in each case ? 

6. Since P traverses the distance Pd in the same time 
that W moves through Wd, what must be true of the rela- 

1 For this value of P take the average of the readings of the spring balance 
as W is drawn slowly upward, and then again as W is allowed to descend 
slowly. In this way the value of the resistance due to friction of the 
pulleys is quite largely eliminated. 



166 LABORATORY LESSONS IN GENERAL SCIENCE 

tive values of the velocities of P (Pv) and of W (Wv) in 
all cases ? 

What are the relative values (a) of P times Pd, and W 
times Wd ; (b) of P times Pv, and W times Wv ? 

(b) With the Cord Attached to the Movable Pulley 

7. Make two other drawings to show the arrangement 
of pulleys, and the values for P and W as directed in para- 
graphs 1 and 2 above, but this time with the end of the cord 
attached to the movable pulley. 

8. Determine the values, and state the relationships 
now apparent as required in paragraph 4 above. 

9. Answer the same requirements as in paragraphs 5 
and 6 above, with the conditions as they are now. 

10. Disregarding any waste of energy due to friction, 
what seems true of the relative value of the work done 
(W times Wd), and of the energy used in doing this work 
(P times Pd) ? 

11. State some of the advantages from the use of pulleys 
as machines (a) over the direct application of any force to a 
body that is to be moved ; (b) over the use of levers of any 
kind. 



XIV. MAGNETISM AND ELECTRICITY 

ELECTROMAGNETS 

1. Bring first one end of a bar magnet and then the other 
to the north pole of a compass needle. Try the south pole 
of the needle in like manner. State what appears true of the 
effect upon each other (a) of like poles ; (b) of unlike poles. 

2. Compare the number of small nails that one pole of a 
bar magnet will support with the number that can be picked 
up (a) when the like poles of two bar magnets are used 
together; (b) when their unlike poles are together. 

3. Put a bar magnet across one pan of a balance, and 
counterpoise it. Bring close above its north pole the south 
pole of another bar magnet, and state the results. What is 
all the time true of the weight of the magnet ? Account for 
what occurred. 

Bring the balance into equilibrium. Repeat the test, 
bringing like poles together. Explain the result. 

4. Observe closely as the teacher connects a "dry cell" 
to the ends of the coil of an electromagnet, and tests the 
effect of the magnet upon nails. 

Determine by trial which is the north pole of the electro- 
magnet while connected with the cell. Mark this pole N. 
Then connect the coil with the cell so that the current is sent 
through the coil in the opposite direction, and test the 
polarity anew. State all the results. 

5. Note about how many nails the electromagnet supports 
when the current is passing through the coil. As carefully 

167 



168 LABORATORY LESSONS IN GENERAL SCIENCE 



as possible let the connection with the cell be broken, and 
note the effect. Repeat several times to be sure of the con- 
dition of the coil as the circuit is (a) opened; (b) closed. 
State the results. 

6. Observe closely the results when the teacher connects 
a dry cell to an electric bell in working order. (Use two cells 

if necessary.) 

Describe the course 
of the current through 
the bell, tracing it very 
carefully with such as- 
sistance as may be 
needed. 

Notice the effect on 
the hammer of the bell 
as the circuit is closed 
and opened. Explain 
(a) why the hammer 
is drawn towards the 
coil; (b) why it flies 
back from the coil. 
Explain how the "make and break" of the circuit is ac- 
complished automatically with the battery connections 
continuously maintained. 

State several possible causes why electric doorbells may 
fail to operate. What may be done to locate the particular 
cause of trouble in order to remedy it ? 

7. Connect a telegraph key into the circuit between the 
battery and the bell; make use of it to close and to open 
circuit, thus ringing the bell at pleasure. Describe the 




Fig. 74. — The 



electric bell, 
operates. 



and how it 



MAGNETISM AND ELECTRICITY 



169 



connection through the key, and explain the use of the 
key. 

8. Substitute for the bell a sounder from a set of telegraph 
instruments, and by use of the key cause the sounder to 
operate. Describe the course of the current through the 
sounder, and its manner of operation as the circuit is closed 
and opened. State (a) when the sounder might operate so 
feebly as to make it impossible to read its clicks distinctly ; 
(b) two ways in which to remedy this. 



ELECTRICITY, AND CHEMICAL CHANGES 

1. Fill the tumbler of 
a simple voltaic cell as 
shown in the cut two 
thirds full of water. 
Have both the zinc and 
the copper strips of metal 
scoured bright with sand- 
paper. To the w T ater 
add sulphuric acid a few 
drops at a time till, as 
the water is stirred with 
the zinc strip, bubbles 
form on the metal sur- 
face somewhat freely. 
These are not air bubbles, 
but the gas is hydrogen 
formed as result of 

chemical change between the acid (H 2 S0 4 ) and the zinc 
(Zn). It has been found by tests made very many times 




Fig. 75. — A simple voltaic cell. 



170 LABORATORY LESSONS IN GENERAL SCIENCE 

that there is formed at the same time one other substance, 
zinc sulphate (ZnS0 4 ), which, so long as the water can hold 
it in solution, dissolves as fast as it forms. When the 
water becomes saturated (filled) with it, the ZnS0 4 will then 
be deposited as a solid. 

2. Chemists have a shorthand way of stating chemical 
changes known to have taken place, and in this case the state- 
ment would be Zn + H 2 S0 4 -> H 2 + ZnS0 4 . The arrow 
points toward the products of chemical change, and in these 
products there must always be the same weight of material 
(and same numbers of atoms of the substances) as found 
in the substances entering into the change. 

3. Test the action of the dilute acid, (a) using the copper 
(Cu) strip in place of the zinc ; (6) putting both strips down 
into the liquid at the same time but not allowing the metals 
to touch each other either within the liquid or outside. 

4. Fasten in place in the cap of the simple cell a strip 
each of copper and of zinc. Connect the binding posts in 
contact with these strips by a copper wire a couple of feet 
in length. Now put the cap in place on the tumbler with 
the metal strips in the liquid close together but not touching 
each other. Observe the strips in the liquid long enough to 
state what change from the former conditions is now noted. 

5. Bring the wire connecting the binding posts down 
lengthwise over a compass needle which is at rest in a north 
and south direction, and note the effect. Repeat several 
times to be sure whether any disturbance of the needle re- 
sults from the presence near it of a current-bearing ("live") 
wire. Note the effect on the compass needle of bringing 
near it and of taking away a permanent magnet. Try a 



MAGNETISM AND ELECTRICITY 171 

piece of iron; then try other substances. Since the wire 
is copper (not iron), what seems to be a characteristic of a 
wire in which a current of electricity is passing? 

6. Repeat the tests upon the compass needle, but this 
time use a dry cell with its binding posts connected by cop- 
per wire. State the results, and their significance. 

7. Cut the wire, joining the binding posts of the dry cell, 
in the middle, and test the effect on the compass needle of 
the wires of the " broken circuit. " Bring the ends of the wires 
together on either side of a thickness of paper, and determine 
if the current completes a circuit through the paper. 

8. Connect the ends of the wires fastened to the binding 
posts of the dry cell to the binding posts in the cap of an- 
other simple cell into which two copper strips have been 
fastened. These copper strips are now the terminals of a 
broken circuit. Put these strips down into a second tumbler 
containing some w^ater, being careful to keep them near 
each other but not touching. By bringing one of the con- 
necting wires down over the compass needle at rest, de- 
termine if the circuit has been closed through the water. To 
the water add a little sulphuric acid and, after stirring the 
liquids well, test the effect of the wire on the compass anew. 
The acid serves as a carrier of electricity across from one 
terminal to the other, and is said to be an electrolyte. Many 
substances in solution would behave in a similar manner, but 
not all solutions are electrolytes. 

9. Repeat paragraph 8, but this time use with the water 
a little copper sulphate (CuS0 4 ) for the electrolyte. After 
some time with the circuit closed examine the copper plates 
for changes in appearance. 



XV. PHENOMENA OF LIGHT 

SHADOWS AND ECLIPSES 

1. Let the room be darkened, and a lighted candle so 
arranged that a well-defined shadow of some opaque body 
is made to fall on a white wall-surface or other screen. By 
moving a sheet of paper back and forth between the screen 
and the body determine how many dimensions a shadow 
actually has, i.e., whether a shadow is a darkened region 
(space) or a darkened surface. That which is seen on a 
screen or wall bears what relation to the real shadow? If 
there had been no screen across the path of the shadow, what 
would have been true of its extent outward ? 

2. Note if there is any sharp line of division between the 
umbra (dark part of the shadow) and the penumbra (the 
lighter outer portion). Determine if the umbra extends 
lengthwise throughout the shadow region. 

Support a sheet of paper so that a pinhole through the 
paper may be moved in turn through the umbra, the pe- 
numbra, and then outside the darkened area. By looking 
through the pinhole towards the candle flame determine 
(a) the reason for the existence of any shadow; (6) the 
cause of the distinction between umbra and penumbra, and 
why they merge without a sharp line of division. 

3. Make such arrangements that enough direct (or re- 
flected) sunlight may come into a darkened room to strongly 
illuminate a small ball that is to represent the earth. 

172 



PHENOMENA OF LIGHT 173 

By use of a sheet of paper moved back and forth in the 
shadow cast by the ball, determine (a) the form of the shadow 
region ; (b) its extent outward (length) ; (c) the form of 
cross section at right angles to the direction of the shadow ;. 
(d) where the base of the shadow is. Leave the screen 
supported in some way in the path of the shadow so that 
cross sections of both umbra and penumbra show upon it. 

4. Making use of a small marble to represent the moon, 
cause it to move round and round the ball in a path (orbit) 
that at times passes (a) through the umbra of the shadow; 
(6) only in part into the umbra ; (c) through the penumbra 
only, or wholly outside the shadow in the region of illumi- 
nation. 

State the conditions that apparently must exist (a) for 
total eclipses of the moon ; (6) for partial eclipses ; (c) for 
failures to have a lunar eclipse every month. From which 
side of the earth with reference to the sun are eclipses of 
the moon to be seen? During which part of the twenty- 
four hours will this be for the observer ? 

5. As the marble (representing the moon) is moved 
around the ball, try to visualize (a) the revolution of the 
real moon about the earth, and in a path such that it comes 
between the sun and an observer ; (6) the onward sweep of 
the moon's shadow across the earth's surface as it approaches 
the observer, envelops him in an " eclipse of the sun" and 
passes on to the eastward beyond him. In so-called eclipses 
of the sun, what really suffers eclipse, i.e., passes into 
shadow? What must be true of the duration of a solar 
eclipse at any station ? 

In what part of the moon's shadow must an observer be 



174 LABORATORY LESSONS IN GENERAL SCIENCE 

that an eclipse of the sun is total rather than partial ? What 
change in the moon's distance from the earth when it is 
directly in line between an observer and the sun will result 
in its not wholly covering the sun's disk? The moon will 
then appear as a dark body, and the sun as a ring of light 
all round the moon's edge — an annular (ringlike) eclipse. 
Make a diagram showing these conditions. 

TnucHiNC ?""* Globs v 
TmicuiNS Sun 




Touching Hun's Globe" 

Fig. 76. — Diagram showing conditions for solar and lunar eclipses. 

6. Total solar eclipses are very rare occurrences for any 
one locality on earth. What evident connection is there 
between this infrequency and (a) the length of the moon's 
shadow ; (6) the size (cross section) of the umbra near its 
apex? 

7. From the diagram above find the apparent reason 
why the moon gets into the earth's shadow (lunar eclipse) 
more often than an observer on the earth is in the moon's 
shadow^ (solar eclipse). 

8. The period of the earth's revolution about the sun is 
somewhat more than 365 days, while that of the moon about 
the earth is 28 days. How many full moons per year are 
possible? How many total eclipses of the moon? As- 
certain from the almanac (or otherwise) how many are to 
occur during this calendar year ? Why are there no more ? 

9. Make a drawing that shows the sun, the earth and its 
moon, and Jupiter with at least one of its moons, so arranged 
as to represent : — 



PHENOMENA OF LIGHT 



175 



(a) Shadows cast by both Earth and Jupiter, and by the satellites 
of both planets, with positions such that eclipses of the moons are 
about to occur in both cases. 

(b) The earth's moon in such a position that an eclipse of the sun is 
about to occur. 





Fig. 77. — The velocity of light was calculated from observations made by 
astronomers of the time-intervals between eclipses of the inner satellite 
of Jupiter. 

10. Astronomers tell us that the innermost of the moons 
of Jupiter is eclipsed at every revolution. Tell several 
astronomical conditions implied in this statement. 



IMAGES BY REFLECTION 

1. Hold a small looking-glass in the sunlight at a window 
and state the effect (a) on the direction of light as it comes 
from the sun ; (6) on the degree of illumination where this 
reflected light now falls. Distinguish between incident rays 
and reflected rays. 

2. Hold a mirror so that the reflected light of a candle 
flame enters the eye. What is seen in the mirror ? Call it 
an image of the flame. Along which rays of light is this to 
be seen ? Why is it seen in this particular direction and not 
in some other? 



176 LABORATORY LESSONS IN GENERAL SCIENCE 

3. With a lighted candle close in front of a looking-glass, 
how many flames are to be seen ? Where does the one that 
is not a real flame seem to be? 

4. Set the lighted candle so that it shall be hidden behind 
a book, but let its image be in sight. State the course of 
the light from the candle flame to the eye. 

Attempt to take hold of what seems to be a candle image 
behind the glass. Move a screen (a sheet of paper) back 
and forth where it seems to be. What is true of the reality 
of this candle image? Call it a virtual image. What kind 
of surfaces form these images? What is the effect of such 
surfaces on the light that falls upon them? 

5. Hold a lead pencil with the point towards the glass. 
In what direction does the pencil image point ? As you look 
in the glass, touch your right hand to your right ear. Which 
hand and which ear of the image seems to be employed? 
(The image is reversed, i.e., turned right and left.) What 
is the relative size of the object and image ? 

6. In front of a looking-glass lay a foot rule perpendicular 
to the mirror. How far back of the mirror does the image 
of the 3-inch mark appear to be? How far back, appar- 
ently, is the 5-inch mark? 

7. On a sheet of paper set a mirror upright (on edge), 
and near it place a ruler somewhat oblique to the mirror 
surface. Draw lines along both the mirror front and the 
marked edge of the ruler. Locate on the latter the 2-inch 
and 4-inch marks. 

Remove the paper, and draw lines from the 2-inch and 4- 
inch marks perpendicularly through the mirror line for some 
distance. Replace the mirror and rule, and note where such 



PHENOMENA OF LIGHT 



177 



perpendicular lines {normals) appear to pass with reference 
to the images of the 2-inch and 4-inch marks. 

8. Draw a line on a sheet of paper to represent a mirror 
surface, and in front of it a 3-inch arrow oblique to this line. 
Having in mind what is suggested in paragraph 7, locate 
the image of this arrow on the other side of the mirror line 
by use of ruler and protractor. 



COLOR PHENOMENA 

Note carefully the procedure as the teacher follows out the direc- 
tions given below. Be ready to state the results obtained, and the 
significance of them as called for in turn. 

1. So adjust a triangular glass prism in a beam of sun- 
light as to get a solar spectrum on a white wall of the room 
(or other screen). 
Then darken the 
room. By use of 
a strip of card put 
over the prism 
faces, determine 

(a) through which 
face the incident 
light enters; 

(b) through which 
the light emerges. 
Call the edge formed 
by the intersection 
of these faces the 
refracting angle of 

the prism, and the side opposite it the "base" of the prism. 
Note (a) whether the change in direction of the incident 




Fig. 78. — Dispersion of light, and the solar 
spectrum. 



178 LABORATORY LESSONS IN GENERAL SCIENCE 

rays is toward the base, or away from it ; (b) which of the 
colors of the spectrum is bent farthest around, and which 
least. Name these colors of the solar spectrum in order, 
beginning with the red. 

A spectrum, whatever the source of light, is defined as 
an arrangement of colors in the order of their refrangibility , i.e., 
according to the degree they are bent from a straight line 
by refraction. Refraction of light by definition is a bending 
of the rays, i.e., a change in the direction of light, by reason 
of changes in the density of medium. (As from air into 
glass, and then from glass into air.) 

2. Using a sheet of writing paper that has been dipped 
into hot melted paraffine to make it translucent, trace the 
emergent rays outward from the prism and note (a) what 
their relative direction is after refraction ; (b) why it is that 
refraction commonly occurs without noticeable dispersion. 

3. Let some one on the far side of the room look through 
a long narrow opening in a cardboard held for him in the 
different color parts of the spectrum in turn, and tell in each 
case what the color sensation is. 

4. Let the spectrum fall upon a plane mirror, and note 
(a) what is done to the light waves giving the spectrum col- 
ors ; (b) whether there has been any change in the relative 
positions of these colors. Explain how it is that all of 
these different colors (light waves) come to every one of 
you, although you are seated in different parts of the room. 

5. Hold a narrow strip of blue cardboard (as pure blue 
as obtainable) in different parts of the spectrum, and note 
its changes in appearance. It is explained that any pigment 
(the material upon which the color of a body depends) re- 



PHENOMENA OF LIGHT 179 

fleets some waves (colors) more largely than others, and ab- 
sorbs the different color elements incident upon it in vary- 
ing proportions. 

Repeat the tests, using in turn cards of different colors. 
(Get as nearly pure colors as can be had.) Explain the 
results as phenomena of selective absorption. 

Explain (a) the green of the grass ; (b) the yellow of gold ; 
(c) the white of any painted house. 

6. With a piece of blue (cobalt) glass so held that light 
from the window comes through it to you, explain selective 
transmission. In like manner use a piece of red glass, and 
explain. 

Now put the two pieces of red and blue glass together, 
and between you and the light from the window. Account 
for the results. 

Observe the spectrum on the screen as first the blue glass 
is put near the prism in the path of the emergent rays, then 
the red glass, and then both glasses. What is the explana- 
tion of these results ? 



XVI. THE EARTH AS A PLANET 

DAY AND NIGHT, AND THE EARTH'S ROTATION 

1. When the sun rose this morning, in what direction was 
it from due east ? (Be ready when called upon to point out 
where the sun rose.) About what time was it? What is 
the time now ? 

Where is the sun now? What has it done (apparently) 
since you first saw it this morning ? In what direction will 
it be at sunset to-night ? Why do you think so ? What do 
you ordinarily mean by (a) sunset ; (6) sunrise ? 

Where will the sun be to-morrow morning? Why is it 
reasonable to expect this? 

2. What is the common distinction between daytime and 
nighttime? Why is the nighttime better for sleep, and 
the daytime better for our varied activities? Name some 
occupations in which men labor all night, and sleep by day. 

How many hours in a day (both daytime and night- 
time) ? From what time to what time may the length of a 
day be best measured? What fractional part of such a 
period is an hour? How are the lengths of minutes and 
seconds determined? Calculate how many minutes there 
are in a day (24 hours). 

3. Hold a cardboard edgewise against the right side of 
the face, thus shutting out of sight objects far around on 
that side. Turn slowly towards the right without change 
of standing place, and state (a) what is found true of the 

180 



THE EARTH AS A PLANET 181 

angular distance of any visible object from the direction 
(plane) of the cardboard as you turn more and more; (b) 
what is found true of the relative distances apart at differ- 
ent times of any two objects in sight ; (c) how far around one 
must turn that an object shall apparently have moved 90 
degrees from the plane of the cardboard. 

4. Repeat the above but w r ith cardboards extending out- 
wards from both sides of the face. State (a) when an 
object may be said to "set" ; (6) how far around one must 
turn that an object which has once "set" may "rise" again ; 
(c) the significance of saying that an object thus coming into 
view, and then disappearing behind the cardboard horizon, 
has an "apparent motion" ; (d) where the real motion exists. 

5. What do you mean by the east horizon of any ob- 
server? By the west horizon? What prevents our seeing 
the sun when it 
is below the west 
horizon ? 

Instead of think- 
ing of the sun as 
moving down be- 
low the west hori- 

. , . P „ Fig. 79. — The horizon at sea. 

zon at nigntlall, 

think of the sun as standing still. Account for the so-called 

"setting" of the sun. What does "sunrise" really mean? 

6. Use a sphere with a heavy wire axis to represent the 
earth, and by means of a thumb-tack fix a spot on the sphere 
that represents your position as an observer in the northern 
hemisphere. Let this same tack hold in place for an horizon 
plane a circular cardboard sufficiently large to have the 




182 LABORATORY LESSONS IN GENERAL SCIENCE 

wire axis reach up through and above it. Turn the sphere 
together with this cardboard horizon on the wire as an axis, 
i.e., rotate the sphere. Note that the east horizon (front 
edge) falls lower and lower below objects which were at first 
out of sight of an observer as located by the tack, thus 
causing them to "rise." Note, too, that the opposite (w r est) 
horizon of the cardboard passes objects and shuts them from 
view, causing them to "set" for the same observer. 

Explain (a) how this exhibits succession of daytime and 
nighttime on the earth; (b) how it is that when we have 
nighttime, and can see the stars, there are people elsewhere 
in the world who are having daytime. 

7. With the sphere and a lighted candle, but without the 
cardboard, note how by turning the sphere on its axis the 
marked place of the observer's position comes around on 
the side where the light is, then passes through the region 
of illumination (daytime), and then on for a period (night- 
time) when the light cannot be seen. 

Repeating such rotation, state when for the observer on 
the earth there occurs (a) sunrise ; (b) noonday ; (c) sunset. 
State (a) how often these occur; (b) when a day's period 
is completed. Why is the sun not seen at all times ? 

8. Define for a rotating body (a) axis; (b) poles; (c) 
equator ; (d) parallels of latitude. 

9. Repeat paragraph 7, holding the sphere so that the 
illumination reaches from pole to pole. State where a line 
drawn from the source of light to the center of the sphere 
cuts the surface of the sphere. Letting the light represent 
the sun and the sphere the earth, state where on the earth 



THE EARTH AS A PLANET 183 

the sun would thus be directly overhead as the earth turns 
on its axis. 

State the relative lengths of the path of the observer 
through the illuminated and the unilluminated regions, and 
of the day and night periods for the observer. 

ROTATION COMBINED WITH REVOLUTION, AND 
CHANGES IN SEASONS 

Upon a crayon box on the table support horizontally an ellipse that 
has been cut from heavy cardboard. Its major axis (long diameter) 
should be at least two feet, and its sides so slightly flattened that it is 
very nearly a circle. Let its circumference represent the earth's path 
around the sun (the earth's orbit). Into a hole a little at one side of 
the center (and toward one "end") crowd a marble nearly halfway 
through to represent the position of the sun in the earth's orbit. 

1. What is meant (a) by an ellipse; (b) by the revolution 
of a body as distinguished from rotation f Around this 
elliptical circumference carry several times the sphere that 
represents the earth, always observing, however, these two 
directions : — 

1. Have the sphere tipped northward so that its axis 
makes an angle of approximately 23|° with a perpendicular 
to the cardboard. (This tips the axis about one fourth way 
over from a vertical position.) 

II. Keep the direction of the axis, no matter where the 
sphere is placed, at all times parallel to this first direction. 
This makes it at all times point towards the North Star in 
the heavens. 

2. Adjust the ellipse so that when the sphere is placed at 
the end of the major axis nearer the marble, the north pole 
of the sphere (earth) is tipped away from the marble (sun). 
Then state : — 



184 LABORATORY LESSONS IN GENERAL SCIENCE 




Fig. 80. — December 21st. 



(a) Where vertical rays from the sun (direction from center 
to center of spheres) fall on the earth relative to its equator. 

(b) What circles on 
the earth are marked 
out by these vertical 
rays, and by those 
rays reaching farthest 
north and farthest 
south, as the earth 
is made to rotate ? 

3. Move the sphere representing the earth a quarter way 
round the cardboard to the right (as one faces the center), 
observing all the re- 
quirements of I and II 
in paragraph 1 above. 
State what is now noted 
as required in (a) and 
(b) of paragraph 2. 

4. Move the sphere 
to the other end of the 
major axis, and farthest 
from the marble. State as in paragraph 2, (a) and (6). 

5. Move the sphere on to three quarters of the way 
around the cardboard, and state as above. 

6. When a complete revolution of the earth about the sun 
is accomplished, what period of time has elapsed? In the 
northern hemisphere, what season of the year is represented 
by each of the four positions of the sphere ? 

7. State in detail why these changes in the position of 
the earth in its orbit cause changes of seasons for us. 




Fig. 81. — March 21st, and September 22d. 



THE EARTH AS A PLANET 



185 



8. Let a sheet of paper, whose edge is cut out to fit down 
over the sphere, be so adjusted perpendicular to the card- 
board that it marks the 
separation of the regions 
of darkness and of illu- 
mination when the sphere 
is placed as in paragraph 
2 above. Rotate the 
sphere, and note the 
relative lengths of the Fig. 82. — June 2ist. 

paths through the daylight and nighttime regions for an 
observer in the northern hemisphere. 

Do the same for the positions as given in paragraphs 3, 4, 
5 above, and state what is apparently true of the relative 
lengths of day and night for each of the different seasons. 




THE MOON, AND ITS PHENOMENA 

(a) Observations 1 

Let every one look for the moon to-night (or on the first clear night), 
as early in the evening as possible, and be ready to help fill out the 
following " Record" from which much concerning the moon and its 
motions may be learned : — 





Date 


Hour 


Shape 


Part of 
Heavens 


Degrees Above 
Horizon 


Apparent Time 

of Rising 

(or Setting) 


— 


— 




— 


— 


— 



etc.. etc. 



1 See footnote of lesson on Temperature Records. It is readily apparent, 
too, that these studies are best begun when the moon is "new." 



186 LABORATORY LESSOXS IN GENERAL SCIENCE 

This record should be made at intervals of two or three days through- 
out a month. If the weather has been unfavorable, continue the ob- 
servations for two months or more. Observe the moon's appearance 
as early in the morning, too, as possible. 

1. On your paper make a drawing to show the shape of 
the moon as you saw it last. At what hour and date was 
this? 

2. Hold at arm's length an orange from which the peel 
has been removed. With the same side toward you all the 
time/ turn completely around where you stand without 
stepping to one side. Let the revolution of the moon about 
the earth be thus represented in the motion of the orange 
around yourself as an observer. 

Select some object in the room as a source of illumination 
(the sun). Using the shell of a half orange to cover the 
unilluminated side of the peeled orange (always, of course, 
on the side opposite the light), note very definitely the form 
of the white (illuminated) part visible to you as seen under 
these several conditions : — 

(a) When the orange is held between the eye and the 
object representing the sun. 

(b) When it is moving through the first quarter of its 
circular path. 

(c) At the end of this quarter. 

(d) When moving through the second quarter. 

(e) At the end of the second quarter, and opposite the 
sun. 

(J) When moving through the third quarter. 
(g) At the end of the third quarter. 

1 One side of the moon is always away from the earth, and a large part 
of that side is never visible from any part of the earth at any time. 



THE EARTH AS A PLANET 187 

North. 




South 

Fig. 83. — The successive changes in appearance (phases) of the 
moon during a month. 



188 LABORATORY LESSONS IN GENERAL SCIENCE 

(h) When moving through the fourth quarter, and in 
conjunction with the sun, i.e., in line with it. 

Now make a series of eight drawings to show these forms 
(phases) of the moon. (Represent the outline form of the 
moon as a circle, and blacken the unilluminated part.) 

(b) Questions on the Data Gathered 

1. When the moon was seen in the west in the early 
evening, state (a) in what direction it was from the sun ; (b) 
in what direction with respect to the sun its "horns" (cusps) 
pointed ; (c) what was the shape of its east edge, and what 
of its west edge ; (d) what was true of its distance from the 
west horizon (and the sun) evening after evening at sunset ; 
(e) its times of setting night by night; (/) the direction it 
was from an observer when it appeared as a "half moon" 
at sunset ; (g) how many degrees (or what fraction of a cir- 
cle) the half moon is from the sun. 

2. Of the full moon, state (a) at what time it rises with 
reference to the time of sunset; (b) what part of a whole 
circle of the heavens it is from the sun ; (c) how long since 
the moon was "new," and how long since it was a half 
moon; (d) what is true of the times of rising night after 
night ; (e) how long from one full moon to the next ; (/) 
which quarter of the moon's revolution has been completed 
when it is full. 

3. From observations of the moon made mornings before 
daylight, state (a) the changes in phase morning after morn- 
ing; (b) the direction of the moon from the sun; (c) its 
distance from the sun morning by morning ; (d) what must 
result in the course of several davs as to the direction of 



THE EARTH AS A PLANET 189 

sun and moon from the observer ; (e) through which quarter 
of its revolution about the earth the moon must have passed 
when seen in the morning as a half moon; (J) to which 
phase the moon comes at the end of the fourth quarter; 
(g) why the moon is not then to be seen for a time. 

4. With the moon full and rising at sunset, what is the 
position of the earth with reference to the sun and moon ? 
At time of "dark moon/' which side of the moon as lighted 
by the sun is towards us? What kind of a body must the 
moon be with reference to giving off light of its own ? 

5. When the moon was new, what was its place of setting 
relative to that of the sun ? What was true in this respect 
when the moon was full? 

6. How many full moons may there be in a year? Ac- 
count for the "months" of our calendar. Ascertain the 
relation of the date for Easter in any year to the time of full 
moon then. 

TIME AND TIME-KEEPING, AND STANDARD TIME 

1. With a string and any suitable weight arranged to 
swing freely from a fixed point of support as a pendulum, 
and with the length from the point of support to the center 
of bob about 25 inches, set the pendulum swinging through 
a small arc, and count the number of oscillations per minute. 
Repeat, with the pendulum length (a) less; (6) greater. 
Upon what does the time for one oscillation seem to depend ? 

2. Make the pendulum length now 36 inches, and count 
the number of oscillations. Find the ratio value to two 
decimal places (a) of the numbers of oscillations for the two 



190 LABORATORY LESSONS IN GENERAL SCIENCE 



pendulums; (b) of the square roots of the two pendulum 
lengths. [Use smaller number for divisor in both cases.] 

3. Make the pendulum length 39 + inches, and count the 
oscillations per minute. 

4. With a stronger force pulling the 
pendulum down, what would probably be 
true (a) of the rate of motion of the pendu- 
lum ; (6) of the number of oscillations per 
minute? Since the force of gravity varies 
in different latitudes, what must be true of 
the lengths of pendulums to make the same 
number of oscillations per minute in differ- 
ent localities? What must be true of the 
lengths of second's pendulums in different 
places ? 

5. Recall the effect of temperature 
changes (heat and cold) upon lengths of 
bodies. What must be true of the pendu- 
lum length in the same clock (a) summer 
and winter; (b) through a day? What 
effect has this on the time for one oscillation 
of that pendulum? What means are em- 
ployed to secure uniform oscillation periods for the same 
pendulum ? 

6. Secure an old clock from which the dial has been 
removed. Find the number of oscillations that allow one 
tooth of the wheel to pass the escapement. Count the teeth 
of this wheel. Calculate the number of oscillations for every 




Fig. 84. — A clock 
escapement. 



THE EARTH AS A PLANET 191 

one turn of this wheel. From the number of oscillations per 
minute of the pendulum (by your watch), determine the 
time required for one turn of this wheel. 

By counting the number of teeth of the pinion of this 
same wheel and of the second wheel into which the pinion 
works, calculate the time for one turn of this second wheel. 
In case a hand were attached to the axle of this second wheel, 
what time interval would be counted off by its every com- 
plete turn? What purpose has a portion at least of the 
wheelwork of a clock? 

7. Note the result as the escapement at the upper end of 
the pendulum is pulled forward by the teacher sufficiently 
to free the first wheel in the train, and the effect of replacing 
the escapement on the rate of the wheel motion. State (a) 
the cause of the motion in the wheelwork; (b) the use of 
the pendulum with reference to such rate of motion. Re- 
call what was true after a time of the motion of the pen- 
dulum in paragraph 1. What is true of the motion of a clock 
pendulum? Explain the difference. Name another use of 
the wheelwork of a clock. What is the sole purpose of the 
pendulum in the clock ? 

8. Calculate the number of seconds in a day. How is 
the natural unit of time we call the day fixed for us ? From 
what time till what time is the true solar day measured? 
Since in a day there are 86,400 seconds, what will be true of 
the relative lengths of these equal parts if the day's length 
varies during the year (as it does) ? 

9. With 86,400 swings of a second's pendulum counting 
off a day-period, what will be true of noon by the clock, 
and noon by true solar time (meridian passage of sun) ? 



192 LABORATORY LESSONS IN GENERAL SCIENCE 

This difference, amounting at different times of year to 
values varying from seconds to about 16 minutes, is the 
"equation of time " (or the "sun fast/' "sun' slow") of the 
almanacs. It must be taken into account in comparing 
clock time and sun time. Clock or "local" noon is deter- 
mined from true noon by adding (or subtracting) the equa- 
tion of time for what particular date ? 

10. What is true of noon local time for you and for places 
(a) eastward; (b) westward? What will be true of the 




STANDARD TIME IN THE UNITED STATES 

Fig. 85. 

watch readings of people keeping local time in towns east 
and west of one another ? What is meant by standard time f 
With the sun neither slow nor fast, by what amount will a 
clock that keeps standard time vary from the true local 
time? 



XVII. THE HEAVENS 

1. Write the names of several stars known to you. Tell 
in what way you recognize any one of these when seen. 

2. Write the names of several groups of stars {constel- 
lations) known to you. Represent on your paper the ar- 
rangement of the brighter stars in any one of these groups, 
thus showing the form by which it can be recognized and 
pointed out to anyone else. 

3. The stars are supposed to be bodies much like the sun, 
and many of them vastly larger. What is the explanation 
for their apparent smallness, and their - lack in heat and 
light ? When only are stars to be seen, and why so ? What 
is the number of the stars? 

4. At what season of the year do the stars generally 
seem to be brightest? What is true of the amount of 
water vapor present in the atmosphere then? What com- 
monly is the cause of any haze overcasting the sky, dim- 
ming the light of the stars or hiding them altogether? 
What differences are there in the appearance of stars other 
than brightness? 

5. What significance has the rising and setting of stars, 
i.e., what occasions it? What is the real name of the so- 
called "shooting stars"? What is their nature? 

6. After some sufficient time (which the weather and 
other conditions will determine), be prepared from obser- 

o 193 



194 LABORATORY LESSONS IN GENERAL SCIENCE 

vations made by you (either with or without assistance) to 
write answers to the following requirements : — 

(a) Whether the path of any star (or constellation) across 
the sky night after night is always the same. 

(b) What is true of the places of rising (or setting) of the 
same star night after night. 




Fig. 86. — Polar constellations. 



(c) The names of several constellations always above 
horizon (that never "set") to observers in your latitude. 

(d) The appearance of the Milky Way. Its place in the 
sky relative to some known constellations. Its real nature. 



THE HEAVENS 



195 



(e) A diagram (at board, or on paper) showing the form 
of the "Big Dipper/' and its position relative to the North 
Star. 

(/) If any change occurs in the brightness of the same 
star night after night, aside from effects of atmospheric 
conditions. 

7. From books and other sources secure information on 
the following topics : — 

(a) The names of the eight planets of our solar system 
in order of their distances from the sun. 




O 

MERCURY 



o 

VENUS 



o 

EARTH 



O 

MARS 



Fig. 87. — Relative sizes of the planets. 

(6) The distinctions between star and planet as to their 
sources of light, and their physical states. 

(c) A diagram to show the relative sizes of the planets. 



196 LABORATORY LESSONS IN GENERAL SCIENCE 

(d) A diagram to show the relative distances of the planets 
from the sun. 



Z 2 > 



[ ^-141 ,000.000 1 4tM1 omnnn 
'--93.000.000 ~ - 4 .30,000 > ,OQO 
-67.000.000 



--881,000,000 



2,775,000,000—' 



--SCjOOOjOOO 



Fig. 88. — Distances of the planets from the sun. 



(e) The views concerning the universe held by the ancients. 
The knowledge Columbus had of the earth's size and form. 




Fig. 89. — Periods of revolution of the planets (length of their years). 

(/) The distance from sun to earth. The time required 
for light to traverse that distance. The time required for 




Fig. 90. — It is calculated that the earth receives about one two-billionth 
of the heat and light given off by the sun. 



THE HEAVENS 197 

light from the nearer stars to reach the earth, and the time 
from the more distant stars. 

(g) The two motions of the moon as the earth moves on 
around the sun in its path of revolution. The meaning of 
the term satellite as applied to the moon. 

(h) The relative intensity (degree) of heat and light from 
the sun upon Mercury, Earth, Neptune. 

(i) The length of the years for the different planets, i.e., 
their periods of revolution around the sun. 



APPENDIX 

LIST OF APPARATUS AND SUPPLIES, AND THEIR COST 

Everything required in these Lessons as apparatus and supplies 
will be found in the equipment commonly provided for teaching the 
high school sciences. Good substitutes for many articles named may 
easily be arranged. It will always be best, however, to have separate 
supplies for the work in General Science, and to have them kept for 
this use only. 

As a reference list when purchases are to be made it will be found 
convenient to note what the Lessons call for as given below. The 
prices named are approximate only, and the articles named may be 
had of any of the supply and apparatus houses. Articles commonly at 
hand anywhere, or readily obtainable at home, are not listed. Collec- 
tions of garden seeds and of grains may be kept in small bottles prop- 
erly labeled, and seeds of various trees may be kept in cigar boxes. 
Such supplies are readily provided for class use during the year. 

Type forms of leaves and roots and flowers, suitably mounted, 
together with exhibits of various rock and ore specimens on cardboard 
(securely sewed in place), are desirable additions to the stock of sup- 
plies. Some of the large industries have "School Exhibits," which 
may be secured at nominal charge ; these show the various stages of 
manufacture of raw materials into marketable products. 

[It is to be remembered that the books and bulletins listed 
elsewhere are considered an essential part of the working 
material for these Lessons.] 

acids : — 

hydrochloric, 1 lb., with bottle $.25 

nitric, 1 lb., with bottle 30 

sulphuric, 4 lbs., with bottle 55 

199 



200 APPENDIX 

alcohol, denatured, 1 quart $ .45 

ammonia, 1 lb., with bottle 30 

balances, specific gravity 4.50 

balances, spring, 64 oz., 2000 grams, each 40 

barometer 15.00 

barometer tube 20 

blast lamp l 3.25 

bleaching powder, can 15 

blowpipe, 8-inch 08 

borax, 1 lb .15 

bottles, wide-mouth, 8 oz 05 

bottles, screw cap, for seeds and grains, 2 oz 06 

burette clamp, iron 30 

candles, small wax, per box 10 

cells, dry, each 25 

cells, simple voltaic 50 

chimneys, student-lamp 06 

compass, magnetic, 2-inch .30 

connectors, double, for battery wires 10 

diffusion shells, 100 X 16 mm. 25 

electric bell, 2§-mch 40 

ether, 1 oz 10 

evaporating dishes, 3-inch .15 

Fehling's solutions, 1 oz. each .15 

file, triangular, 6-inch .10 

filter paper, pkg. of 100, 10 cm 10 

funnel, 3J-inch 14 

glass cutter, 5 wheel .30 

glass jar (J gallon battery jar) 20 

glass plates, blue and red, each 2" X 3" .05 

glass tubing, J-inch, 5 lbs 2.00 

graduate, 100 c.c 50 

iodine solution, 2 oz . .20 

1 Some means must be provided for heat in case the room for General 
Science does not have gas burners. A plumber's torch is very satisfactory. 
Pipettes and elbow tubes may then be made as needed from glass tubing. 



APPENDIX 201 

jug, one gallon $ .35 

labels, box 08 

lever holders 30 

limewater (to be made) 

litmus paper, sheets, red and blue, each 04 

magnets, bar, in box, per pair, 6-inch 45 

magnet, electro-, 3-inch 1.25 

magnifiers, watchmaker's 40 

mercury, 1 lb., in bottle 1.50 

metric (foot) rules, 1 dozen 35 

meter stick, brass tips 35 

mirror, plane, 6-inch strips 10 

mortar, 3-inch 36 

paraffine, 1 lb 16 

potassium chlorate, 1 lb 35 

prism, equilateral, 3-inch 25 

protractors, manilla card 06 

pulleys, triple-tandem, pair 2.25 

pumps, glass models, lift and force . 2.65 

rings tand, 2 rings, 18-inch 40 

rubber stoppers, — 

one -hole for test tubes 03 

two-hole for wide-mouth bottles 12 

rubber, thin sheet, per sq. ft 30 

rubber tubing, fe -inch, 12 ft 75 

shears, common, 5-inch 50 

sodium bicarbonate, 1 lb 10 

sodium carbonate, 1 lb 10 

sphere (toy globe) 10 

spoons, iron, tea, per doz 25 

sugar, grape (glucose), 1 lb 10 

telegraph key 1.15 

telegraph sounder 2.00 

test tubes, 6 X f inch, per dozen 25 

test tube brush 05 

test tube rack, wood 25 



202 APPENDIX 

thermometer, chemical, C. & F $ .80 

thistle tube 08 

vaseline, bottle 05 

weights, metric, set, 1 to 500 grams 1.75 

weights, metric, fractional, each 05 

wire, copper, No. 22, insulated, J lb 30 

wire gauze, asbestos center, 5" X 5" .09 

wire, iron, No. 24, annealed, 4 oz. 16 

wire pliers, side-cut, 6-inch 70 



A LIBRARY LIST OF REFERENCE BOOKS 

Books should be considered tools for the use of pupils. 
To learn to use them aright is fundamental in school work, 
and one of its chief aims. Knowing where to find needed 
information, coupled with a desire for knowledge, constitutes 
no small part of an education. In the books listed below, 
there is provided a fund of information on the topics of these 
Lessons that is worthy the best efforts of every pupil. 

One book generally suffices as a text in any subject in 
school work. But in General Science no one book is likely 
to provide all the material that very properly comes under 
discussion. In some cases it may be desirable to have 
several copies of the less expensive books where these are 
of superior worth and usefulness. For class instruction 
this is often wiser than to make the same outlay for single 
copies of all the books named. To have the use of only 
one book in General Science, however valuable the results 
attained may be, is to suffer somewhat the same limitations 
as does the carpenter who for tools has but a jackknife. 
The skilled mechanic selects from his large assortment that 
particular tool best suited to his purpose. 



APPENDIX 203 

Teaching conditions may render impossible any extended 
use of reference books, but no apology is needed for having 
provided a generous reference list. The use of these books 
and others of like character will enrich the course. While 
library equipment and the preferences of instructors may 
make desirable many substitutions in any list named, it is 
urged that the greatest care be exercised in the selection 
of references. 

Where a double period for daily laboratory and class 
work is arranged, no lesson preparation outside those hours 
will be necessary. In addition to recitation and experi- 
mental work there is in this arrangement an opportunity 
under favorable conditions to teach pupils how to study, 
and to direct their desire for knowledge along lines that offer 
the largest educational values. 

Bailey (Mac), Sanitary and Applied Chemistry $1.40 

Bengtson & Griffith (Mac), The Wheat Industry 65 

Bigelow (Mac), Applied Biology 1.40 

Blakeslee & Jar vis (Mac), Trees in Winter 2.00 

Brownell (T. P.), Lessons in Physics 75 

Brownell (T. P.), Lessons in Chemistry 50 

Caldwell & Eikenberry (G.), General Science 80 

Clark (Am.), Introduction to Science 1.20 

Coleman (Mac), Hygienic Physiology 60 

Coleman (Mac), The People's Health ., .70 

Conn (G.), Bacteria, Yeasts, and Molds 1.00 

Coulter, J. G. (Am.), Plant Life, and Plant Studies .... 1.20 
Coulter & Patterson (Ap.), Practical Nature Study .... 1.35 

Crawford (Hi.), Nature Study Lessons 75 

Doty (Ap.), Prompt Aid to the Injured 1.50 

Freeman & Chandler (G.), World's Commercial Products . . 2.75 

Goff (Co.), Principles of Plant Culture 1.00 

Harper (Mac), Animal Husbandry for Schools 1.40 



204 APPENDIX 

Harrington (Ap.), About the Weather $ .60 

Hessler (San.), First Year of Science 1.25 

Hooker (Am.), Child's Book of Nature, Part III 50 

Jewett (G.), The Next Generation .75 

Kinne & Cooley (Mac), Foods and Household Management . 1.10 

Lipman (Mac), Bacteria in Relation to Country Life ... 1.50 

Parloa (Cen.), Home Economics 1.00 

Price (Wi.), Handbook on Sanitation 1.50 

Price (Sm.), The Land We Live In ... 1.50 

Rowell (Mac), Introduction to General Science 75 

Snell (Mac), Elementary Household Chemistry 1.25 

Snyder (Mac), Chemistry of Plant and Animal Life . . . . 1.50 

Tarr (Mac), New Physical Geography 1.00 

Tarr & McMurry (Mac), New Geography, Second Book . . 1.10 

Warren (Mac), Elements of Agriculture 1.10 

Williams & Fisher (Mac), Elements of Theory and Practice 

of Cookery 1.00 

Wilson & Warburton (Web.), Field Crops 1.50 

The free use of high school science texts serves many 
excellent ends. Aside from the information for immediate 
use furnished by them in a concise, attractive, and reliable 
form, pupils with active minds will scarcely fail to find in 
some one of these fields of science that which will arouse a 
desire to go beyond a course in general science. Texts and 
manuals in Agriculture, Botany, Chemistry, Geology, Home 
Economics, Meteorology, Physics, Physical Geography, 
Zoology, etc., should have extended use as reference books 
in connection with General Science. 

The publishers of the books listed above are as follows : — 
(Mac.) The Macmillan Company : New York. 
(Ap.) Appleton & Co. : New York. 
(G.) Ginn & Co. : Boston. 
(Am.) American Book Co. : New York. 
(Wi.) Wiley & Sons : New York. 



APPENDIX 205 



(Hin.) Hinds, Noble & Eldredge : New York. 
(Cen.) Century Company : New York. 
(T. P.) The Torch Press : Cedar Rapids, la. 
(Co.) Co-operative Company : Madison, Wis. 
(Sm.) Small, Maynard & Co. : New York. 
(San.) Benj. Sanborn & Co. : New York. 
(Web.) Webb Publishing Co. : St. Paul, Minn. 



LIST OF BULLETINS 

U. S. Department of Agriculture, Washington, D.C. 

Farmers' Bulletins l 
No. 

54 Some Common Birds. 

55 The Dairy Herd. 

106 Breeds of Dairy Cattle. 

128 Eggs, and Their Uses as Food. 

134 Tree Planting on Rural School Grounds. 

157 The Propagation of Plants. 

173 Primer of Forestry, Part I. 

181 Pruning. 

183 Meat on the Farm. 

218 The School Garden. 

245 Renovation of Worn-out Soils. 

249 Cereal Breakfast Foods. 

255 The Home Vegetable Garden. 

266 Management of Soils to Conserve Moisture. 

1 Order through the Congressman from your district. It will be well to 
have several copies each of some of these Bulletins. All give valuable 
information in form available for teaching. One of the purposes of their 
publication is school use. No charge is made for them. 

It is suggested that provision be made for the proper care of all Bulle- 
tins from their first use. One good way is to bind them more or less durably 
into sets of related titles, with labels giving the bulletin numbers and names 
in each set, and then as needed these sets can be put out for use protected 
by covers such as are used with magazines in public reading rooms. 



206 APPENDIX 

No. 
270 Modern Conveniences for the Farm Home. 

287 Poultry Management. 

293 Use of Fruit as Food. 

298 Food Value of Corn and Corn Products. 

345 Some Common Disinfectants. 

355 A Successful Poultry and Dairy Farm. 

358 Primer of Forestry, Part II. 

363 The Use of Milk as a Food. 

369 How to Destroy Rats. 

375 Care of Food in the Home. 

377 Harmfulness of Headache Powders. 

389 Bread and Bread-Making. 

393 Habit Forming Agents. 

413 The Care of Milk, and its Use in the Home. 

447 Bees. 

450 Facts about Malaria. 

463 The Sanitary Privy. 

473 Tuberculosis. 

475 Ice Houses. 

478 How to Prevent Typhoid Fever. 

491 Profitable Management of Small Apple Orchards. 

492 The More Important Insect and Fungous Enemies of the Apple. 

493 The English Sparrow as a Pest. 
607 The Farm Kitchen as a Workshop. 
617 School Lessons on Corn. 

630 Some Common Birds Useful to the Farmer. 
679 House Flies. 

Bulletin 100, Bureau of Chemistry $0.10 

Circular 125, Bureau of Animal Industry 0.10 

Circular 19, Division of Publications Free 

(A list of the Publications of the Department of Agriculture Classified 
for Teachers.) 
Circular 29 on Stock Judging, Purdue University : La Fayette, Ind. 

(Agricultural Extension) $0.10 

Board of Health of your State, — Rules and Regulations . . Free 



APPENDIX 207 

REFERENCES FOR CLASS ASSIGNMENTS 1 

I. The Hoi an Body 

1. The hand — Bigelow, pp. 519-522; Coleman (Physiology), pp. 16- 

23; Crawford, pp. 14-17. 

2. The mouth — Bigelow, pp. 465-468; Coleman (Health), pp. 109- 

113; Coleman (Physiology), pp. 102-103, 152-157, 243. 

3. The eye — Bigelow, pp. 515-518; Crawford, pp. 5-7; Coleman 

(Physiology), pp. 248-255. 

II. Heat in Relation to the Human Body 

1. Combustion — Brownell (Chemistry), pp. 13-14, 34-38. (Any 

good text in Chemistry.) 

2. Ventilation — Price, pp. 15-41. 

3. Respiration — Bigelow, pp. 110-114, 502-506, 526-528; Coleman 

(Physiology), pp. 104-121 ; Coleman (Health), pp. 20-41 ; Doty, 
pp. 170-177. 

4. The human body as an engine — Bigelow, pp. 492-499 ; Coleman 

(Physiology), pp. 138-141. 

5. Regulation of body temperature — Bigelow, pp. 522-524, 533-555. 

III. Health and Well-Being 

1. Keeping well — Coleman (Physiology), pp. 201-214; Coleman 

(Health), pp. 1-8. 

2. Infection — Bigelow, pp. 276-297, 554-560 ; Coleman (Health), 

pp. 11-19, 114-130; Coleman (Physiology), pp. 122-132, 267; 
Conn, pp. 100-138, 203-266; Doty, pp. 91-111 ; Farmers' Bulletin, 
No. 345; Lipman, pp. 1-25; Price, pp. 269-285; Regulations of 
the State Board of Health. 

3. Sanitation — Bailey, pp. 106-116; Coleman (Health), pp. 190-214; 

Lipman, pp. 56-98; Bulletin 100, Bureau of Chemistry, U. S. 
Dept. of Agriculture, pp. 8-11; Farmers' Bulletins, Nos. 270, 
375, 478. 

1 Make free use of any good texts in General Science for all these lessons. 
Use the Index of any text to find the desired information quickly. If one 
text does not have what is wanted, consult another. 



208 APPENDIX 

4. The water supply and health — Coleman (Health), pp. 42-55; 

Price, pp. 46-52. 

5. General health problems — Bailey, pp. 79-91, 297-307; Bigelow, 

pp. 312-314, 393-397; Coleman (Health), pp. 74-92, 132-152, 217- 
260; Conn, pp. 139-181; Doty, pp. 203-219; Lipman, pp. 103- 
134,431-446; Price, pp. 54-71 ; Circular 125, Bureau of Animal 
Industry, U. S. Dept. of Agriculture ; Farmers' Bulletins, Nos. 345, 
369, 450, 459, 473. (Various Bulletins from the State Board of 
Health.) 

6. Life, growth, rest, and recreation — Bigelow, pp. 13-21, 44-57, 

122-126; Coleman (Health), pp. 8-11, 153-163; Coleman (Phys- 
iology), pp. 1-13. 

7. Stimulants and narcotics — Bailey, pp. 257-287 ; Bigelow, pp. 539- 

554; Coleman (Physiology), pp. 27, 100, 151, 180, 214-237; Cole- 
man (Health), pp. 164-176; Farmers' Bulletins, Nos. 377, 393; 
Jewett, pp. 118-125, 136-152. 

8. General science and right living — Jewett, pp. 1-6, 126-135, 153- 

188 ; Warren, pp. 5-35. 

IV. Matter and Force 

1. Some properties of matter, and changes in matter due to force — 
Brownell (Physics), pp. 9-14, 19-23, 107-109. (Any good text in 
Physics.) 

V. Water, and Its Uses 

1. Some properties of water — Crawford, pp. 173-182; Hooker (Part 

III), Chaps. XV-XXI. 

2. Vaporization and condensation — Coulter & Patterson, pp. 235- 

240 ; Harrington, pp. 66-98 ; Tarr, pp. 244-250. 

3. Heat of vaporization, and of fusion — (Any good text in Physics.) 

4. Solution, absorption, diffusion — Brownell (Physics), pp. 20-22, 109. 

(Any good text in Physics.) 

5. Osmosis in the human body and in plants — Bigelow, pp. 88-97. 

6. Study of a stream. 

7. Valley formation, and surface erosion — Crawford, pp. 145-149 ; 

Tarr, pp. 50-68. 



APPENDIX 209 

VI. The Atmosphere 

1. Some properties and uses of air — Hooker (Part III), Chaps. I, II, 

IV, VI, X-XIV; Tarr, pp. 229-230. 

2. Pressure exerted by the atmosphere — (Any good text in Physics.) 

3. Applications of atmospheric pressure — Brownell (Physics), pp. 

54-59, 114-115; Hooker (Part III), Chaps. V, VII. 

4. Causes of change in atmospheric pressure. 

5. Currents in the atmosphere — Harrington, pp. 48-59 ; Tarr, pp. 

255-262. 

6. Areas of high and low pressure — Harrington, pp. 99-127 ; Tarr, pp. 

262-271. 

VII. Weather and Climate 

1. Weather in the affairs of men — Harrington, pp. 1-32, 187-222; 

Lipman, pp. 52-55; Tarr, pp. 83-89, 105-108, 275-279, 369-392. 

2. Weather as affected by highs and lows — Harrington, pp. 128-135, 

142-165; Tarr, pp. 285-293, 426-427. 

3. The thermometer — (Any good text in Physics.) 

4. Temperature records. 

5. Solar heating — Crawford, pp. 182-184. 

6. General weather records. 

VIII. At Our Homes 

1. Rooms of the house, and their furnishings — Bailey, pp. 25-38, 48- 

60; Coleman (Health), pp. 177-190; Farmers' Bulletins, Nos. 270, 
463, 475, 607; Kinne & Cooley (Foods), 15-53, 265-277, 352-364; 
Parloa, pp. 1-26, 35-167, 268-278; Price, pp. 72-113; Snell, pp. 
59-81; .Williams & Fisher, pp. 11-23, 31-49. (Trade catalogues 
giving cuts of heating systems and plumbing outfits.) 

2. Cost of living — Bailey, pp. 308-321; Coleman (Health), pp. 93- 

108; Coleman (Physiology), pp. 166-179; Farmers' Bulletin, No. 
375; Kinne & Cooley (Foods), pp. 54-83, 278-294, 321-331, 342- 
351; Parloa, pp. 168-201, 222-261 ; Price, pp. 187-202 ; Williams 
& Fisher, pp. 73-82, 136-191, 226-247. (State Food Laws, and 
Regulations of the State Board of Health.) 

3. Fires, and burns — (Bulletins of the State Fire Warden, and regu- 

lations of the local fire officials.) 



210 APPENDIX 

4. Accidents other than burns — Coleman (Health), pp. 299-302; 
Coleman (Physiology), p. 266; Doty, pp. 148-151, 182-202. 
(Bulletins from the State Commissioner of Labor, as well as from 
local labor officials.) 

IX. Household Chemistry 

1. A review of some chemical changes. 

2. The chemistry of cleaning — Bailey, pp. 92-105 ; Kinne & Cooley 

(Foods), pp. 365-378; Parloa, pp. 300-311; Snell, pp. 105-113, 
121-126, 143-161, 243-253. (Any good text in Home Economics.) 

3. Acids, bases, and salts — Snell, pp. 82-104, 114-120. (Any good 

text in chemistry.) 

4. Some carbonates. (Any good texts in Chemistry, and Geology.) 

X. The Home Surroundings 

1. A garden in the home life of a family. 

2. The care of a garden — Farmers' Bulletins, Nos. 218, 255; Freeman 

& Chandler, pp. 254-263; Goff (selected parts). (Catalogues of 
some reliable houses dealing in flower and garden seeds, tools, etc.) 

3. Tree planting — Farmers' Bulletins, Nos. 134, 157, 173, 181, 358, 

468; Warren, pp. 216-234. (Catalogues of any extensive and 
reputable Nursery.) 

4. Trees of the neighborhood — Blakeslee & Jarvis, pp. 195-209 (and 

other selected parts) ; Coulter & Patterson, pp. 162-167 ; Farmers' 
Bulletin, No. 468. 

5. Some plant studies — Bigelow, pp. 66-85, 156-231. (Any good 

text in Botany or Plant Biology.) 

6. Birds about our homes — Bigelow, pp. 428-436 ; Coulter & Patter- 

son, pp. 112, 122-124, 303-313; Crawford, pp. 39-42; Farmers' 
Bulletins, Nos. 54, 493, 630. 

XI. Local Industries 

1. Some occupations of the community. 

2. Modern industrial life — Tarr-McMurry, New Geography, Second 

Book (selected parts). 



APPENDIX 211 

3. Sanitary conditions for the wage earner. — Jewett, pp. 189-195; 
Price, pp. 151-186. 

XII. The Farm, and Our Food Supplies 

1. The hen — Crawford, pp. 35-38. 

2. Eggs — Bigelow, pp. 58-64; Farmers' Bulletin, No. 128; Harper, 

pp. 378-381. 

3. Poultry keeping — Farmers' Bulletins, Nos. 128, 287, 355; Harper, 

pp. 307-348; Warren, pp. 368-371. 

4. The horse — Harper, pp. 3-102, 349; Jewett, pp. 34-42 ; Circular 29, 

Experiment Station, Purdue University. 

5. Cows and the dairy industry — Bailey, pp. 228-237, 242-256; 

Coleman (Health), pp. 56-73 ; Conn, pp. 182-202 ; Crawford, pp. 
27-33 ; Farmers' Bulletins, Nos. 55, 106, 183, 363, 413 ; Harper, 
pp. 105-194; Lipman, pp. 357-430 ; Price, pp. 203-268 ; Warren, 
pp. 323-350; Williams & Fisher, pp. 92-101, 291-295; Circular 
125, Bureau of Animal Industry; Circular 29, Experiment 
Station, Purdue University. 

6. Some foodstuffs — Bailey, pp. 128-206 ; Farmers' Bulletin, No. 389 ; 

Kinne & Cooley (Foods), pp. 138-157, 209-246; Williams & 
Fisher, pp. 59-71, 102-135, 259-262. 

7. Lessons on corn — Bigelow, pp. 149-151; Farmers' Bulletins, Nos. 

298, 617 ; Freeman & Chandler, pp. 50-58, 65 ; Warren, pp. 156- 
178; Wilson & Warburton, pp. 47-131. 

8. Apple raising as an industry — Conn, pp. 40-52; Farmers' Bulle- 

tins, Nos. 293, 491, 492; Freeman & Chandler, pp. 263-278; 
Kinne & Cooley (Foods), pp. 87-108; Warren, pp. 248-270. 

9. Wheat, and wheat growing — Bengtson & Griffith (selected parts) ; 

Freeman & Chandler, pp. 1-20; Farmers' Bulletins, Nos. 249, 
389; Wilson & Warburton, pp. 135-472. 

10. Other foodstuffs — Bigelow, pp. 100-110, 460-462, 474-476 ; Conn, 
pp. 56-99; Freeman & Chandler, pp. 65-113; Kinne & Cooley 
(Foods), pp. 126-137, 187-208. 

11. Origin and nature of soils — (Any good text in Agriculture.) 

12. Soil conditions for plant growth — Bigelow, pp. 85-88, 97-100; 
Coulter & Patterson, pp. 280-287 ; Farmers' Bulletins, Nos. 245, 
266, 408; Lipman, pp. 144-263; Warren, pp. 76-87, 91-95. 



212 APPENDIX 

13. Usefulness of plants to man — Farmers' Bulletins, Nos. 173, 358; 
Freeman & Chandler, pp. 278-297. 

XIII. Work and Machines 

1 . Meaning of the terms work and energy — (Any good text in Physics.) 

2. Classes of levers — (Any good text in Physics.) 

3. Pulleys — (Any good text in Physics.) 

XIV. Magnetism and Electricity 

1. Electro-magnets — Brownell (Physics), pp. 84-85, 129. (Any good 

text in Physics.) 

2. Electricity and chemical changes — (Any good texts in Physics and 

Chemistry.) 

XV. Phenomena of Light 

1 . Shadows and eclipses — (Any good texts in Astronomy, Physical 

Geography, and Physics.) 

2. Images by reflection — Brownell (Physics), pp. 71-74. (Any good 

text in Physics.) 

3. Color phenomena — Hooker (Part III), Chaps. XXVII-XXVIII. 

(Any good text in Physics.) 

XVI. The Earth as a Planet 

1. Day and night and the earth's rotation — (Any good texts in As- 

tronomy, and Physical Geography.) 

2. Rotation combined with revolution and changes in seasons — Tarr, 

pp. 397-401. (Any good texts in Astronomy, and Physical 
Geography.) 

3. The moon and its phenomena — Crawford, pp. 185-187. (Any 

good text in Astronomy.) 

4. Time and time-keeping, and standard time — (Any good texts in 

Astronomy, and Physical Geography.) 

XVII. The Heavens 
Tarr, 1-6. (Any good text in Astronomy.) 



INDEX 



Accidents, 90-94, 122. 

Acids, 97-100. 

Adenoids, 6. 

Air currents, 59-62. 

Air, weight of, 58-59. 

Albumen, 126, 153. 

Alcohol, 34-35, 92. 

Amusements, 33-34, 89. 

Antiseptic, 22. 

Antitoxin, 22. 

Apple raising, 146-150. 

Artesian wells, 27. 

Atmosphere, 52-62. 

Atmospheric moisture, 42-44, 59- 

61. 
Atmospheric pressure, 54-62, 75-76. 



B 



Bacteria, 20, 32. 

Bacteriology, 20. 

Baking powder, 153. 

Barometer, 55-56, 59-61. 

Base, 97-100. 

Bathroom, 81. 

Bedrooms, 13, 81. 

Birds, 115. 

Blood, 18, 20, 48. 

Blood poisoning, 22. 

Bones, 2. 

Buds, 108-109, 112-113. 

Burns, 90. 

Business ability, 101, 116-121, 144, 

150. 
Butter, 134-136. 



Canning, 31, 136-137, 146. 
Carbonates, 98-100. 
Carbon dioxide, 11, 98-100. 



Cells, 32. 

battery, 167, 169-171. 
Chemical changes, 9-10, 46, 94-100, 

169-170. 
Chemical equations, 98-99, 170, 
Chemistry of cleaning, 96-97. 
Cisterns, 28. 
Clay, 154-155. 
Climate, 73-76. 
Clocks, 190-192. 
Clothing, 18, 87. 
Color phenomena, 177-179. 
Combustion, 9-12, 90. 
Condensation, 42-44. 
Constellations, 193-195. 
Corn, studies on, 111, 138-146. 
Cost of living, 84-89. 
Cow, the, 132-133. 
Cyclone, 62, 65. 

D 

Dairying, 134-135. 
Day and night, 180-183. 

relative lengths of, 183, 185. 
Density, 38, 52, 54, 58-62. 
Diffusion, 44-48. 
Disinfection, 24, 96. 
Drugs, use of 35. 
Dust in relation to health, 95. 

E 

Eclipses, 173-175. 
Eggs, 125-126, 128-129. 
Electric bell, 168. 
Electricity, 167-171. 
Electrolyte, 171. 
Employers' liability, 93. 
Energy, 160-162. 

of the human body, 17, 32-34. 
Erosion, 49-51. 
Eye, 6-8. 

213 



214 



INDEX 



Fermentation, 94-95. 

Fire extinguisher, 91. 

Fires, 90-92 

Flame, 10-11. 

Flies, 26, 30. 

Food elements, 126, 135-137, 152- 

153. 
Food preservatives, 31, 94, 137. 
Food supply, 84-86,' 102-105, 125- 

126, 133-137, 151-153. 
Forces, 38-40, 44-46. 
Fruits, 146-147, 149. 
Fulcrum, 162-163. 

G 

Gardening, 86, 101-105. 
Germination, 142-143. 
Germs, 20-23. 
Growth, 32, 37. 

H 

Habits, 34-35, 37. 

Hand, 1-3. 

Health, 19-37, 122-123. 

Heat equator, 61. 

Heat from the sun, 72-74. 

Heating plants, 83-84. 

Heavens, the, 193-197. 

Hen, the, 124-125. 

"Highs" and "lows," 60-62, 65-68. 

Horizon, 181-182. 

Horse, the, 129-132. 

House, rooms of, 77-84. 



I 



Images by reflection, 175-177. 

Incubators, 128. 

Inertia, 39. 

Infection, 20-29, 95. 

Irrigation, 65. 

Isobars, 65-68 

Isotherms, 65-68. 



Joints, 2. 



Laundry, 83. 

Leaves of plants, 106, 108, 112-114. 

Levers, 162-163. 

Life, 31-32. 

Lungs, 14-16 

M 

Machines, 160-162. 
Magnets, 167-171. 
Matter, 38-40. 

properties of, 38-42, 51-53. 
Meat, 86, 133. 
Milk, 134-137. 
Molecular motion, 45-48. 
Molecules, 39. 
Moon, the, 185-189. 
Mosquitoes, 26, 30. 
Mouth, 3-6. 
Muscles, 1-5, 33-34. 



N 



Narcotics, 34-36. 

O 

Occupations, 101-102, 116-119. 

for children, 101-102, 119. 
Osmosis, 46-48. 
Oxidation, 9-12, 17. 
Oxygen, 9-14. 

P 

Parallels of latitude, 182, 184. 

Patent medicines, 36. 

Pendulum, 189-191. 

Perspiration, 17-18. 

Phases of the moon, 186-189. 

Planets, the, 174-175, 195-197. 

Plant studies, 105-114, 147-148. 

Plants, usefulness of, 157-159. 

Plumbing, 78. 

Poultry, 126-129. 

Properties of matter, 38-42, 52-53. 

Protein, 126, 153. 

Protoplasm, 31. 

Pulleys, 163-166. 

Pumps, 56-57. 

Pure foods, 26, 31. 



INDEX 



215 



Quarantine, 23. 



Q 



R 



Rainfall, 42-43, 64, 75-76. 

Rats, 30, 83. 

Recreation, 33-34, 89. 

Reflection of light, 175-178. 

Refraction of light, 177-178. 

Rents, 87-88. 

Respiration, 14-17. 

Revolution, of bodies, 173-175, 183- 

189. 
Roots, 105-106, 111-112, 139. 
Rotation of bodies, 180-185. 
Rubber, 159. 

S 
Salt, 97-100. 
Sand, 154-156. 
Sanitation, 24-31, 122-123. 
Satellites, 175, 197. 
School attendance, 120-123. 
Secretions, 6, 18. 
Serum, 21-22. 
Shadows, 172-175. 
Sickness, 19-26, 29. 

prevention of, 19, 36. 
Silos, 146. 
Siphon, 57-58. 
Skin, 3, 18. 
Soap, 96-97, 137. 
Soil air, 157. 
Soil, cultivation of, 104, 143. 

nature of, 154-155. 
Soil waters, 155-157. 
Solar system, 195-197. 
Solution, 44-48. 
Spectrum, 177-179. 
Standard time, 192. 
Stars, 193-197. 
Sterilization, 22. 
Stimulants, 34-36. 



Streams, study of, 48-51. 
Stress and strain, 39-40. 



Teeth, 5-6. 

Telegraph, key and sounder, 168-169. 

Temperature, 69-76. 

of body, 17-19. 
Theory, 160. 
Thermometers, 69-70. 
Time-keeping, 189-192. 
Toxins, 21-22. 

Transportation, 117-118, 144, 147. 
Trees, for fruit, 106-107. 

planting of, 105-107, 147-148. 

pruning of, 107. 

spraying of, 149. 

studies of, 107-111. 
Tuberculosis, 13-14. 
Typhoid, 23. 

U 
Universe, 196. 

V 
Valleys, 49-51. 
Vapor, 10, 43, 90. 
Vaporization, 42-44. 

heat of, 43-44. 
Ventilation, 12-14. 

W 

Wage earning, 119-121. 
Water, 11, 41-44, 96. 
Water supply, 27-29 ■ 
Weather, 63-68, 73-76. 
Weather forecasts, 64, 76. 
Weather maps, 65-68. 
Wells, 27-28. 
Wheat, 150-151. 
Wheelwork, 190-191. 
Wind, 53, 60-62, 75-76. 
Work, 162. 

Z 
Zenith, 60. 



Printed in the United States of America. 



T^HE following pages contain advertisements of a 
few of the Macmillan books on kindred subjects. 



NEW BOOKS FOR 
SECONDARY SCHOOLS 



Elementary French Reader 



By LOUIS A. ROUX, A.B. 

Officier d'Academie ; Master in French, Newark Academy, 
Newark, N.J. 

This is an attractive collection of stories and poems, 
short prose selections from the classics, and some lively 
anecdotes. 

A questionaire follows each story and the vocabulary is 
quite complete, including even the irregular verb forms, the 
irregular plurals and feminines found in the text. The 
book is designed for beginners and provides interesting 
reading matter in the simple vocabulary of every-day 
French. 



A Brief Survey of 

English and American Literature 

By FREDERICK M. TISDEL 

Associate Professor of English in the University of Missouri 

A treatment of the essentials of the literature of England 
and America in a book of about 200 pages. Just the text 
for the busy high school course. 



THE MACMILLAN COMPANY 

Publishers 64-66 Fifth Avenue New York 



NEW BOOKS FOR 
SECONDARY SCHOOLS 

Social Problems: A Study of Present-Day Social Conditions 
By E. T. TOWNE 

Professor of Economics and Political Science, Carleton College 

A treatment of such social problems as Immigration, 
Child Labor, the Sweating System, Unemployment, Crime, 
Poverty, and Conservation, brought within the comprehen- 
sion of the average high school student. It deals largely 
with facts and with an analysis of conditions and is a 
sane though vigorous presentation of these very modern 
problems. 



Dairy Farming 

By C. H. ECKLES 

Professor of Dairy Husbandry in the University of Missouri, and 

G. F. WARREN 

Professor of Farm Management in Cornell University 

Written in response to a demand for a book in which 
the principles and practice of dairy farming are clearly 
and systematically set forth, this book will doubtless find 
wide acceptance both in schools and among farmers who 
are interested in dairying. 



THE MACMILLAN COMPANY 

Publishers 64-66 Fifth Avenue New York 



NEW BOOKS FOR 
SECONDARY SCHOOLS 

Salesmanship 

By S. R. HOOVER 

High School of Commerce, Cleveland, Ohio 

This is an extremely practical treatment of the art and 
science of selling. The book treats of selling only, but it 
discusses constructively every detail that enters into good 
salesmanship. It is a book for every pupil whose life will 
fall along commercial ways. As the author points out, 
every one at some time sells something, and if his only 
commodity is his labor or his service, he will find a better 
market if he is familiar with the psychology and the ethics 
of closing a bargain. 

The main divisions of the book are : Salesmanship; the 
Salesman ; the Salesman's Preparation ; the Customer ; the 
Process of the Sale ; the Demonstration ; Closing the Sale; 
Finding and Correcting Mistakes ; Relations between De- 
partment Managers and Salesmen ; Suggestions from a 
Selling Letter ; Department Store Instructions ; the Sales- 
man's Rewards. 



Constructive Geometry 



By EARLE RAYMOND HEDRICK 

Professor of Mathematics in the University of Missouri 

It is the purpose of this book to furnish drill in geo- 
metrical conceptions, as well as in the application of 
geometrical principles to practical uses. A few simple 
methods of construction are given which, by careful analysis 
and detailed development, fully satisfy the questioning 
mind of the young student, and give him a foundation in 
thoroughness and care. The early exercises are simple 
and well graded. 

THE MACMILLAN COMPANY 

Publishers 64-66 Fifth Avenue New York 



NEW BOOKS FOR 
SECONDARY SCHOOLS 

Laboratory Exercises in Agriculture 

By JOHN H. GEHRS 

State Normal School, Warrensburg, Missouri, and 

J. A. JAMES 

Department of Agricultural Education, University ofWisconsin, 
Madison. Wis. 

A group of stimulating and up-to-date exercises for use 
in connection with the beginning course in general Agri- 
culture. The work is arranged for use in the laboratory 
and the book is made on the slip-sheet plan, blank sheets 
being included between the printed pages. 



Elementary Algebra — -Second Year Book 

By FLORIAN CAJORI 

Of Colorado College, and 

LETITIA R. ODELL 

Of North Side High School, Denver 

A book which connects in style and in subject matter 
with Elementary Algebra, published last spring. The 
same features that have made that little book so immedi- 
ately popular, characterize the Second Year Book : crisp, 
vigorous presentation, insistent drill and a generous use of 
practical applied problems. 



THE MACMILLAN COMPANY 

Publishers 64-66 Fifth Avenue New York 



